I can't remember but what exactly did the Avengers post M-Day do for mutants? Outside of put Sentinels outside the mansion for their protection or put then in a concentration camp? I honestly wasn't reading Avengers books then so I don't know the answer on how helpful they were to mutants in the aftermath of M-Day. Or even after Genosha. SO with that said, unless they did something their inclusion for a memorial honoring those lives lost on M-Day feels like an unwarranted invitation. And certainly Wanda would not be welcome.