What Does The Partnership Mean?
Marvel TV and Fox working together is a big deal and it means they're willing to talk and trade/sell rights. We suspect there's more than money involved in sharing licensing and such, and the partnership could, just maybe, mean that Marvel is getting certain rights in return on the film side. This does not mean the X-Men are joining the MCU. They aren't and won't for a very, very long time. The X-Men universe is massive and successful on its own and Marvel doesn't have a use for them anytime soon (especially with their Inhumans filling that same role).
This deal now means it's beneficial for Marvel to again promote Fox's X-Men franchise on their channels (website, social media, Comic-Cons, comics, etc.) and it's a guarantee that movie rights have been a topic of conversation between Fox and Marvel Entertainment. That means there's a real possibility - now more than ever - that something can, is, or perhaps already has been worked out regarding the rights to the Fantastic Four and the attached library of cosmic characters that we know Marvel Studios very much wishes to use. Perhaps that's why Marvel Studios dated three more films for 2020 last week...
We've reached out for comment on whether or not Legion and Hellfire take place within the X-Men movie universe and will update when we learn more.
Dates have not yet been set for the FX's Legion and Fox's Hellfire (working title) pilots.