The reason for Punk giving such a tepid return promo is due to the fact that Warner Brothers Discovery demanded it, as part of their finalizing their deal with Endeavor for the Raw TV rights.

WBD are still spellbound by Punk and super pissed at Tony for letting the nobodies run him off. Hence them making the unprecedented move to secure Raw as a replacement for AEW since all confidence is gone with Tony and AEW.

WWE had to get Punk back to get the deal with WBD and for Punk to have the juice to force Hunter to take him back as opposed to telling him to eat shit and going to say FX/Disney or staying with USA Network? Punk has to eat shit and be a big boy and play nice. Which meant that his return promo had to be neutered and generic since he has to show WBD that he truly was the grown up persecuted by the unruly Cali cosplay wrestlers conspiring against him.

It's fully expected that Raw arriving on TNT/TBS will indeed mean the end of AEW, though it's left unsure if they will be canceled outright once the deal is done as one last "fuck you" from Warner Brothers Discovery to Tony for fucking them over. Or if they'll be allowed to ride out their contract to give Tony time to find a new home for the company.

Either way, Punk isn't going to be buried. Expect Raw to basically become the CM Punk/Cody Rhodes show while Smackdown becomes the Roman Reigns Coconut Theater Palladium as far as roster reshuffles go next draft.