Yep. X-Men gives them plenty to work with if they want to wait until after Phase 6. I feel like Secret Wars is gonna be absolute bonkers enough without the inclusion of 616 X-Men. They can use Deadpool and Wolverine from whatever they want to call the Fox X-Men universe, but I don't think Deadpool is going to be considered 616's Deadpool, despite being an MCU movie.I wouldn't be surprised if they keep a full-on X-MEN movie in their back pocket to anchor Phase 7. Maybe introduce a few characters individually leading up to that in Phase 6.
If we remember back to the end of Deadpool 2, they were traveling through realities (or wolverine was) and I think that is how they are going to bring them over. Sort of part of the MCU and they get to have fun here, but they aren't "ours" so to speak. I could easily see Deadpool getting killed off in a beautifully gory way in Secret Wars.
Here's the full phase 6 slate of dates: