I'm not entirely sure that Hickman required cooperation from the Avengers office to use Wanda. Marvel made a huge deal a year ago about how HoX/PoX/DoX was all supposed to be this huge important return for the X-Men franchise, and that kind of talk sometimes comes with an abundance of resources and newfound authority. I can see a scenario where Hickman says "I wanna write Wanda," and either the Avengers office says yes to not rock the boat with the higher-ups, or the Avengers office says no but the higher-ups overrule them.
Not saying that's what happened. Maybe there's even something out there I don't know of that said it was cooperative with the Avengers book. I'm just saying I could see it work out that way.
As for Uncanny Avengers, I question how much of that behavior was writer and how much was editorial. Or if it was equal parts. Comments from both basically fed the issue.