Yeah but what you're saying right now is very different from what I'd call a "heavy cinematic flair", as you put it earlier. To me "heavy cinematic flair" means the whole game will be centered around it, that means cutscenes everywhere and "cinematic gameplay" when not on cutscenes and stuff like that. Think God of War, and such.
By the way, there have been Metroid games with cutscenes in the past, and it wasn't just Other M. Prime 3 had them too, they tried going more "cinematic" with it in trying to tell a more comprehensive story, and in my opinion, failed atrociously. The story drags Prime 3 down so much. That isn't to say Metroid games can't have good stories, but it's only worked once (Fusion) out of the three times they tried putting more emphasis on it, and that shows they're just not that good at making story-centric games, which also isn't to say a game has to be story-centric for its story to be any good, as I'd say Super Metroid has one of the best stories in the series and nearly all of it is told in subtle ways that don't involve any dialogue or cutscenes.
Personally, that's the kind of story I'd want from a Prime 4, but, I'm not expecting it. Prime 1 was quite a letdown story-wise to me (scan logs were great for lore and world-building, but the events you took part in yourself didn't really have much going on), and from then it never really got any better with Retro's next games, even though they did increasingly try to do the storytelling stuff with the Prime series.
I just hope it will have a compelling story and will look like a modern game and not like an HD-version of a game from the late 90'/early 00'.
Why is nobody talking about Kensuke Tanabe. I think he is much more to worry about than Retro Studios. He's the producer of Metroid Prime: Federation Force!