so they had other plans for what you could do with that kind of material and how you could put it out there and get the audience’s appetite warmed up for it
Hell yeah, I want that Tatum Gambit film or at least a duo or trio if not solo (eg. Gambit & the Externals). The MCU is multiverse after all, so any proper MCU X-Men would be untouched, still separate. They could even purposefully make that portal lead to one of the Wolverines' home worlds, like say that Age of Apocalypse's one, or the brown vs Hulk one, etc. So even an R-rated universe, not necessarily Deadpool's own. They have endless options to choose from. Multiverse yet still contained.