That's Marvel for you. They create these familial bonds with characters and then proceed to do nothing with them. Like, when was the last time Bruce Banner even spoke to any of his kids? Hell Jimmy Hudson is wandering around 616 somewhere and yet will probably never interact with Logan and has never interacted with Laura since arriving in 616.
I can see some good arguments for the Scarlet Witch joining the X-Men - she needs to put the whole Decimation thing to rest, it could open up some interesting relationships with those who trust her and those who don't (Yost's "Astonishing X-Men" nodded to this by having Kurt invite her to the school and Northstar being annoyed at this), plus Nightcrawler is literally the only superhero she could have a romance with and fans would not roll their eyes at this point.
Mostly I'm just bored with the Avengers line hardly ever using her, and if they won't put her back on the main team or ever let her speak to her old friends like Carol, then Yoshida might just as well take her away from Brevoort and give her to someone who will use her.
It is strange how many missed opportunities there have been to feature Wanda in the X-Men books over the years - I mean pre-Decimation. The '90s were maybe her prime decade for the number of comics appearances, and that was also the X-Men's prime decade for popularity, but you almost never saw her in an X-Men comic except during the Onslaught crossover and that one damp squib of a crossover that was "Bloodties." She was so completely identified with the Avengers line that she was the only mutant who "died" in Onslaught (and Reed Richards gave an excuse for why she could go that looks very much like Mark Waid staring at the art at 3 in the morning and trying to come up with something) while Pietro went back and forth between the two lines.
There is some interesting story material that could be mined from that, but as I said earlier, "Uncanny Avengers" really blew the chance to deal with the difference between being an X-mutant and the resident mutant of the Avengers. And that was probably the last chance for a while.
At this point, I'm not even sure if it's worth retconning the retcon. The MCU already established a Wanda with no relation to Magneto and that's going to be the most mainstream version of her. It'll be ridiculous if they re-retcon the same thing again. I'd like it back though since their relationship was really good. But Wanda was always an Avengers character first.
As for the M-Day nonsense, I've pretty much moved on from it a long time ago. People who are still mad about it should just deal. But for the sake of not pissing X-fans off, I'd just leave her in Avengers books