Do you really feel it's a truly "new entry" other than in name/lore when:
1. You conveniently lose all your moves at the start?
2. You once again have to get the charge beam, morph ball, power bombs, space jump, screw attack, grappling hook, speed boost, and gravity suit which are all re-used moves?
3. That the ending which I will not spoil is almost just the "2.5D" version of a previous retro entry, followed by that same entry's token timed event?
4. And that this does, indeed, follow the core maze-like, backtrack-access methods of its previous entries?
The things I listed above are factual rather than based on opinion: there is a LOT this game does to focus on nostalgia more than it does new:
1. EMMI fights devolve into only two scenarios until you get the (unexplained on how "absorbing" an EMMI brain gives) Omega cannon: either run like hell; or stealth your way passed. I never ended up even mentioning it because it was neither bad nor good. It was a surprise to me that they focused so much on that in the trailers/marketing when in the grand scheme of things, it was actually quite minor and quickly fell into the background for me as I crossed those territories.
2. The only new moves are dashing, melee counters, and cloaking. The dashing was nice, but hardly ground-breaking, the melee counters were mostly useful for bosses and feeling cool sometimes (most of the time, you could just blast your way through mobs, and you could actually do that with bosses, too), and the cloaking was really only for EMMIs. I can tell these were carefully added in WITHOUT being a strong mechanic focus because it might ruin the core formula, and I am certain they didn't want to change things up too much.
And that last line is why we'll likely not agree about this: it is very clear to me they did NOT want to change things up too much! They absolutely wanted to appease the nostalgia of the fanbase, otherwise they would have gone more like Fusion or Other M which both broke the mold far more. Though, I wouldn't say the visuals were "revamped" when there really isn't a Switch reference point for this other than DKC: Tropical Freeze (which actually looks superior in many ways, tbh...). As I said in the review, they did what they could with limited hardware power even if it just pails in comparison to just about anything modern.
In closing, though, my score shouldn't have been a surprise. I think you put more negative connotation on "retread" than I did. I was also very clear that the game's graphics looking terrible really isn't the devs fault. I mean, they're working with 2015 hardware and probably would have been better off targeting 30fps so that they could pretty it up a bit. The load times are already a bit questionable as it is for how little it's actually visually doing when MHRise exists, and even DKC:TF gives this game a run for its money (and even looks better at times because they're not using film grain and low lighting to hide things).
Don't worry, I also played through all of the Metroid games as well as other games in the genre like the Ori games and Bloodstained and Symphony of the Night and Hollow Knight. And a bit of Axiom Verge. This knowledge isn't exclusive to you.
About your "facts"... Metroid Dread re-uses things from previous games is fact. Saying it does so to be nostalgic or that it makes it a retread is an opinion. And when you're in an opinion-based discussion and treat your opinion like a fact, it's just annoying. So don't do that.
1. Losing all moves at the start is necessary for a game like this. Teaching players new moves as they progress is what makes the genre what it is. If you start with everything from the previous game and then add more and more on top of that, it'll be a complete mess. If you don't add anything over the course of the game, it's not even a metroidvania. It's actually a really convenient complaint because Metroid is the only series in the genre with multiple sequels starring the same protagonist in a continuing story, which means other metroidvanias don't need to address the issue at all.
2. Actually, I lied a bit up there, because Ori is also like that. Ori conveniently loses all power-ups (except walljump) between the first and second game, for reasons never addressed, and then has to get double jump, sticky (previously known as climb), dash, bash, triple jump, water breath and more, all over again. It's part of what makes a sequel. You can't drop everything the previous games had, you're supposed to build on them, and you do that by keeping the best elements, improving on them, and ditching the bad things. Which both Metroid Dread and Ori and the Will of the Wisps did.
3. I literally have no idea what you're talking about. I can see the escape sequence part being especially reminiscent of Super Metroid, but still, it's a series staple - something you don't ditch, you maintain and improve upon, and Super had the best escape sequence of the series so it only makes sense. As for the rest of the ending, it's wholly original and extremely unlike literally any other Metroid game, which all end with you fighting some brainless monstrosity. If anything, it was Fusion that had the "retread" kind of ending, what with the whole "being saved by your supposed enemy" feeling entirely like a cheap attempt at redoing the ending of Super Metroid. I saw none of that in Dread.
4. Are you actually serious dude. That is literally what the genre is. Guess they should make the next Metroid open-world, that'll be innovative.
So to answer your question, yes. I really feel it's a truly new entry other than in name/lore. And also in lore it's fresher than anything this series has had in a very long time. If anything, I find it particularly funny that you use Fusion as an example of a game that shook the formula, because it fails at all those 4 criteria as well.
You're also wrong about the new moves. I mean, for starters, one of those three isn't even new. Melee counter was already a thing. It was certainly revamped in this game, because of how much it slowed everything down in Samus Returns, so they made it faster and snappier, added two variations (melee dash and air counter), and made it so it's less centralizing. But still it's not new. What's new is slides, the Phantom Cloak, the Diffusion Beam, the Spin Boost (albeit only a weaker version of the Space Jump, which already existed), the Cross Bombs, the Storm Missiles (though they are basically the Seeker Missiles from Prime 2, but still new to the 2D series), and obviously the Flash Shift which is a total gamechanger. I'm not sure if I'm forgetting or if that's all of them, but it's plenty and I'm pretty sure it's more new stuff than Fusion. Or Super, for that matter.
They also changed old abilities and expected progression path. The melee counter was revamped as I said earlier, and free aim can be done while running now as well. The morph ball takes shockingly long to get, which makes traversal very different than in other Metroid games, and comes pre-equipped with the spring ball now. The Varia Suit now no longer protects you from cold areas, meaning they now differ from hot areas in the game's progression. The speed boost can now be maintained through several actions it couldn't before, such as landing, walljumping, and even morphing and unmorphing, and also shinesparks can now be performed in all directions as both a morph ball and... not morph ball. Shinesparks and screw attacks are also useful in several boss fights now, something that was never the case before (barring one specific boss that can be shinesparked in Super Metroid). The Gravity Suit was usually handed to you right after going through your first water section, but in Dread you will spend a long time underwater, even fight a boss in it without getting Gravity as a reward until much, much later, which makes it a cathartic pickup again like it hadn't been since Super Metroid. I could go on, but yes, there is a lot of new meaning in finding most of these old abilities, and even if some are kept the same, they did because sometimes you just don't need to change it. If it ain't broke, don't fix it. There's a reason so many metroidvanias have a double jump upgrade. It works.
As for your last few points... you said the game would have been better off had they targeted 30fps to pretty it up a bit... yeah, man, no thanks.
tl;dr Don't call your opinion a fact. And especially, don't do it when you're getting a lot of the 'facts' wrong. If you think of Dread as a retread, I disagree with you. If you say it's factually a retread, I think you're wrong.