I'd love it to happen, but it won't be in. If it was in, it would be such a game changing feature, they would have teased it in some way. The big addition is almost certainly imo going to be the Retro Mode gimmick. Hopefully I'm wrong as I'd bloody love an expansion draft franchise mode, but I'd be very surprised if they added something so significant without making a big deal about adding it.
I think it would be great, in the future, if you could create your team and use it in DD AND/OR Franchise/Season mode.
In Franchise/Season mode you could just replace a team. (I don't have any interest in facing my favorite team)
You could either take over the players on the team your replacing or have a draft. Maybe the draft could be like the Battle Royale draft, that's a different style and fun.