There is a lot of conflicting information on whether or not Dylan will be back filming soon, especially since he's allegedly been cast in the new Michael Keaton movie "American Assassins", which is supposed to start filming in August. There was a Teen Wolf con over the weekend and some people who attended claim that the cast confirmed he would be back, and some people who attended insist there was nothing definitive. (I'm inclined to err on the side of "nothing definitive" because most of the guests at that con are no longer on the show and likely wouldn't know Dylan's plans.)
I mean, there is definitely not going to be any Maze Runner stuff. They weren't very far into filming when they had to shut down production and I don't think there's a set date to start back up again.
Whether or not Dylan shows up is still up in the air. So far no cast members have been listed for any of the Teen Wolf things (and trust me, there are a lot), they just say "the cast of Teen Wolf". I'm waiting to hear back about press, and if he is going to be there he would probably do press, so I can let everybody know if he is listed (assuming I get in).