I just don’t think his MMA career matters for Punk’s reception as a “work wrestler” - Kay Fabe is dead. Jericho legit subdued Goldberg in a few seconds back when Goldberg was supposed to be the Hulk. HHH, Seth Rollins, and John Cena all have worked victories over Brock Lesnar when everyone knows he’d likely annihilate them in a real fight. Kenny Omega and others have demonstrated for publicity how they can make literal dummies and children “manhandle” them in a “match.” Jake Hagar and Wardlow did an entire “worked” MMA fight.
What people are going to care about is how well Punk handles promos and holds up his end of the choreographed/improvised matches that pro-wrestling is about. Just because we now have a fun story to tell about the reality versus the fiction doesn’t mean the fiction won’t still be entertaining as hell.