A variant cover for X-Men/Fantastic Four from Marvel's February 2020 solicitations showing Doctor Doom grabbing flowers in his fists hints that the Fantastic Four archenemy may have a major clash with the X-Men's new home, the sentient island Krakoa. The upcoming mini-series will focus on what the ramifications of mutantkind leaving the human world for Krakoa in Powers of X and House of X have for Reed and Sue Richards' son, Franklin, an Omega-level mutant with the ability to warp reality.
House of X #1 and solicitations for X-Men/Fantastic Four #1 teased a confrontation between the X-Men and the Fantastic Four over the future of Franklin Richards, who as a mutant has birthright citizenship on Krakoa. However, the solicitations for X-Men/Fantastic Four #2 also suggested Dr. Doom will intervene in events, stating, "The world has been re-shaped by the X-MEN. But you can’t reshape a world without encountering its true master...DOOM."
The vibrant flowers on the cover are likely the flowers of Krakoa. These plants have actually played an important role in writer Jonathan Hickman's new take on X-Men. Not only do Krakoa's flowers have incredible medicinal properties, they can be used to create new physical landscapes on Krakoa. These properties make the flowers a natural target for Doctor Doom, although what role he will play in X-Men/Fantastic Four has yet to be shown.
X-Men/Fantastic Four is written by Chip Zdarsky (Peter Parker: The Spectacular Spider-Man, Marvel Two-in-One) with art by long-time X-Men artists, Terry and Rachel Dodson.