#3 They might not get a chance to go back

The trend among the superstars leaving WWE is to lash out against their former employers in whatever opportunity they get.
We all heard what Jon Moxley had to say about WWE in Chris Jericho's podcast. Even Jericho himself once said that he is banned from the WWE and they have removed him from their annals of history.
How Brock Lesnar ruined another wrestler's career - Watch Now!
While Jericho and Moxley can get away with what they said, it might not be the same for the other superstars. We've seen many former WWE superstars ruin their chances of going back by trash talking the company in public. Either they'll get sued or get erased from the company's history.
WWE has been offering big money contracts to their talents to prevent them from signing with AEW. While some like Mike & Maria Kanellis have decided to stay, the others leave against the company's will, which could blow their chances of going back.