The X-Men have lots of adventures in space, but introducing the concept to the films would be a good way to shake the franchise up and give it some new energy.
The Dark Phoenix storyline is largely set in the cosmos, with the emergence of the Phoenix Force causing the X-Men to be pulled into an intergalactic conflict.
The X-Men movies have kept things relatively grounded, but you can’t have a sentient, all-powerful, cosmic energy being in the shape of a bird without having your head in the clouds.
Plus, going cosmic has paid off big time for the MCU, so I wouldn’t be surprised to see some teases in the trailer that the X-Men are heading for the stars.