#3 Easy way out
WWE is notorious for putting long-term contracts in place which many a time deters its wrestlers from moving to the other wrestling promotions. At the same time, WWE is notorious for frustrating its wrestlers by putting them in storylines that don't do justice to their talents. Dean himself has been a victim of something like this for more than a year now(which makes it a very legitimate question to ask why he would re-sign with them).
Dean himself may ask for a way out whenever he feels the booking and his character are not going anywhere (under some terms and conditions of course). With a viable option in AEW blossoming and taking definitive shape, many wrestlers would be looking to negotiate their contracts on similar terms.