Certain types of games exist and thrive due to what's technically feasible at the time they're created, just like any other form of art.
An example, Cuphead isn't radically different from something like Metroid in terms of gameplay and yet Cuphead was technically impossible when Metroid was all the rage. Similarly Metroid's asthetic is a product of it's era and wouldn't be received today in the same way.
Games are art, they simultaneously drive the medium while being limited by it.
Usage of real recorded instruments can still be technically challenging today if you want to do what Monkey Island 2 did with its audio via iMuse - synchronization between music and in-game events (easier) and smooth background music transitions between rooms (harder). MI2 Special Edition recorded its soundtrack with real instruments and while it did a pretty good job at it, it still noticeably simplified some transitions the original version had, because they were much easier to achieve back when it was using MIDI.
Although one reason for that (other than the obvious MIDI vs. sampled one) could be that in MI2, a lot of effort went into this music system which ended up working great, but... not many people actually noticed ;)
I mean, for an 2D adventure game, you are basically animating characters. The objective is to create something like an animation movie, in whatever art style you want. It doesn't need to push the tech in the same style that the first games where.
Which is great! I want them to be spending their efforts in the game, artwork, narrative, puzzles, jokes, etc, not on how to create a background that looks OK if you have an EGA screen and a recognisable melody in a PC speaker.
Whether is pixel art or not is irrelevant to me, as long as it's well drawn and animated. I just hope that they end with a fantastic result. I'll sure buy it and play it when it's out.