I mean the obvious one gotta be what if Nash and Hall never leave WWF for WCW?
No curtain call ever happens so Triple H never gets punished and he goes on to win the KOTR instead of Austin. So that means no Austin 3:16 promo and Austin probably remains as “The Ringmaster”, never to really shoot into stardom. nWo never happens to the same level so there’s a possibility that the Monday Night Wars doesn’t happen which means WWF maybe never goes into the Attitude Era which fucks a lot of things up and there’s no wrestling boom.
Hell, DX doesn’t happen either so HHH never becomes The Game and stays as “Hunter Hearst Helmsley” while Road Dogg and Billy Gunn still become a tag team just not as successful as they become as part of DX.
Eh, Austin was already turning into the Stone Cold character by April 1996, him not getting that Austin 3:16 promo may not have immediately shot him up to relevancy, but it's not like he still wouldn't have had the feud with Bret Hart (which is what actually made him a top guy).
What's more likely to happen is that Shawn doesn't lose his smile and just drops the belt to Nash or Hall because of course he would. WrestleMania 13 would likely be a Bret/Nash/Hall show and Shawn would maybe face off against Vader or Austin.
Austin still becomes a main eventer regardless, just with less pull because of the kliq. Hunter Hearst Helmesley likely suffers the most of anyone because without the trials and tribulations and without DX, he doesn't become a main eventer.
All that being said, I don't see a scenario where Hall or Nash stay. The money they were being offered by WCW was insane and even if for the sake of hypotheticals you want to say WCW weren't interested, then Vince would obviously undercut the two and try to get them to take less to come back.