They probably just didn’t want to do it at the time
I feel like it’s coming though
Olsen wants wanda to interact with the x-men and be the daughter of magneto too
I mean they didn't have to do it THIS TIME. It served absolutely NOTHING to anything with the series whatsoever. But they did just to inexplicitly tell us mutants exist in the MCU.
I've would've rather had it where the x-gene been dormant but after the blip, it activated it, it'll make more sense without being complicated.