I have that same feeling.
It certainly reeks of desperation and going back to the well.
I am not as certain I would characterize it as desperation as I am as an effort to play it safe. My reasoning is based on each phase's planning, the pre-planned production of both upcoming movies, and the hiccup that impacted both. Here is the timeline of how things got from there to here:
Avengers: Endgame was a Phase 3 production. It was announced in October 2014. The movie began filming in August 2017. Disney announced the studio was acquiring Fox the following December. The mega merger was finalized in March 2019, around a month before A: E debuted in theaters. Disney assimilated film and television rights for The X-Men and Fantastic Four properties.
Three years pass.
Avengers: Doomsday and Avengers: Secret Wars are Phase 6 productions. They were announced in July 2022.
At some point, Kevin Feige and crew began conditional discussions of how the mutants and the FF would be integrated into the Marvel Cinematic Universe. I would guess initial conversations began when Disney said it was gunning for Fox in late 2017.
After the
A: E theater run began, Disney announced the already pre-planned Phase 4 the following July. The phase's purpose was the introduction of the post-Thanos big bad: Kang. Jonathan Majors' March 2023 legal problems caused the studio to revise its Phase 5 and Phase 6 plans.
This is my hypothetical of what went down. Before July 2019, Feige's crew first gambled on and was later justified using a huge ensemble cast with
A: E. They approached the drawing board for the Multiverse saga with the assumption of duplicating the same box office success with the same tactic.
However, I thought the next huge ensemble cast would be composed with many X-Men actors, new FF actors, the Chrises Hemsworth and Evans (to tie-in the old and new group), and actors who made appearances along the way like Hailee Steinfeld, etc. I would have never guessed them returning Robert Downey, Jr. for any new role.
If I assumed correctly, A: D's massive casting was pre-planned seven years ago and that the studio believed throwing a ton of faces into the mix would work just as safely as the first time. I believe any desperation was thrown into the mix after the decision was made to ditch Majors and deciding which villain would replace Kang.