Yeah, that definitely seems to be the direction they're heading in.
spoilers:end of spoilers
Not for nothing did they put Xavier in the iconic yellow hoverchair with the 90's theme playing in the background in Dr. Strange: Multiverse of Madness.
I think you have a point. I think the MCU tends to default either to the most 'iconic' era of a character, or the stories/eras that makes the most sense when you want to reinvent the character for modern audiences. Iron Man, for instance, arguably got a modern 'reboot' of sorts with stories like Extremis (which is where the Afghanistan retcon to the origin was first introduced) so that's what formed the basis for the MCU take on the character (granted, back in 2008, that was the most recent version of the character!). Likewise, The Ultimates really reinvented the Avengers for the 21st century (not to mention Nick Fury), so that series served as the basis for the MCU Avengers, blended in with elements from the original 60's comics.
With Spider-Man they've kinda gone with a blend of the iconic 60's Lee-Dikto run and its many modern reinterpretations, including Miles Morales' early stories from Ultimate Comics...though they've thrown in elements from more modern 21st century stories since that's the era that saw Spider-Man becoming an Avenger and working more closely with other heroes.
I think the same may apply to the X-men. They'll probably go with some blend of the 90's (the animated series in particular) and the Claremont era...perhaps with some elements of successful 21st century runs like Morrison's run or Hickman's run thrown in. Actually, something like the new X-men '92 comic adaptation of the Krakoa era might be a good indicator of how MCU X-men films might approach the material.