She's a permanent member of the team. She's on the cover for issue 23
I did look at the original poster for the team and have theories on the roles.
Weapon_X_Vol_3_22_Textless.jpg
Domino &
Yuriko are in their same spots. So probably no change in their character or roles.
Creed is in Logan's old spot because he's the leader now rallying the team for whatever.
Omega Red is in Warpath's old spot. The new muscle, strongest team member, and possibly the leaders #2 and most supportive ally, like James was to Logan.
Mystique. She's in Creed's old spot. So MAYBE their relationship will be antagonistic. She'll be the wild card who does what she wants, regardless of the team & take issue with the way Creed runs things, just like he did with Logan. And she'll probably be just as hard to reign in. Then in the end, she'll betray & usurp him, which fits her narrative.
Just a thought, but Lord knows. Pak may not have given it much thought. I may have analyzed more than he did. lol