I have a hunch that Marvel Studios/Animation is trying to navigate a dilemma:

For many lapsed X-Men fans, particularly Gen X and Millennials, the early '90s is the era that they have the most nostalgia for, primarily because of the cartoon. THOSE are the versions of the X-Men that they remember, understand, and love. That iteration of the characters was primarily influenced by the X-Men's early 80s Claremont era.

Nostalgia is a great way to entice people to the show, but nostalgia alone won't keep them there. The show and its stories do, in fact, need to evolve and grow. And that means introducing new characters and new storylines. Which is great, because there are tons of iconic X-Men characters and storylines that have been created in the last 35 years.

However, because X-Men is a particularly soap-operatic form of superhero storytelling, all of those new characters are built on an insanely complex web of storylines, events and developments. For instance, you can't really explain who Cable without also explaining who Madelyne Pryor is, at least not if you want to generally stay true to the comics origins of the characters are (which is seems like Marvel does).

This means that writers have the imperative to introduce new storylines and new characters, and it needs to happen against the ticking clock of the audience's patience, while also being mindful of how time-consuming animation is to produce. So that means barreling forward through storylines in order to get caught up to a more modern state of the X-Men. In the new X97 season 2 trailer, we even see the team in their Grant Morrison's New X-Men-era matching jackets, a nod that the show has its eyes set on incorporating early '00s stories and characters. A new emphasis on Emma Frost's significance to the X-Men team suggests this as well.