the thing is - would Punk be happy being controlled? I'm not sure.
I also think that beyond popping a rating, he's a draw but not the draw ppl keep claiming him to be. Yes his merch sales were top, but he was also getting more new shirts with actual good designs and he's a legacy draw. If you look at the ratings (I know, boo me), beyond his initial return from suspension (which was also the debut of a new show to get a boost) his segments don't pop ratings. In fact the only thing that popped a rating was MJF Cole showing up. So yes, he is popular and brings a fanbase...but they don't really translate to viewership bumps or ticket sales.
Not to mention, they already sell out all the time, so what is the point of potentially nuking your locker-room over a few crowd pops and then clearly identifiable diminishing returns.
He will also demand a gigantic salary when you have other people you need to re-sign in the short and medium future.
Would he be beneficial to WWE in a legends - part time deal? sure
Would Punk accept that role and agree to be kept on an even tighter leash - and possibly also look like the world biggest hypocrite? I genuinely don't know
But I do think people want him back more for the drama than anything - and they really should think beyond their fantasy booking before they start convincing themselves this is what they want. People are already excusing the fact he assaulted his boss and pretending what he did in AEW would never happen in WWE because it can and it has in times past.