I also loved magical express, but I don't see it returning. It's a lot of moving parts, and it's not just on Disney. Between the state becoming less dunno, I don't want to start drama, less Disney friendly?, deals with the airport (which they needed, especially for luggage) would be harder to re-implement, as its an exception that must be granted. Many more are content to take ride shares, and that number was growing significantly even while we still had magical express.
I suspect the message being sent to disney, from both other companies/entities and guests is it was time to phase it out. I think a large portion of dis board folks would love to have it back, but reading from other disney groups, friends, etc, many prefer ride shares .