I would agree, or I would argue, if I remembered anything that made it "dated" I played Tombi (the original) last in 2009, and it was perfectly fine for me then.
Tomba! 1 seems mostly harmless outside of some strange difficulty curve jumping and crap boss "fights" - 2, on the other hand, is INCREDIBLY dated, imo! Poor pacing; lots of filler; the 2.5D mechanics don't work as well as in the first game, due to the 3D graphics; the game becomes a Metroidvania lite but only out of nowhere, after like five hours; so on and so forth. (I just did a review of the game a few days ago, so a ton of this is fresh in my mind!)
Remaking that one could certainly take a lot more time unless they do it spot for spot, and leave in all the problems!
You should check out my YouTube channel, The Golden Bolt! I review all types of video games, both classic and modern, and I also give short flyover reviews of the free games each month on PlayStation Plus to tell you if they're worth downloading. After all, the games may be free, but your time is valuable!