Q: Is there any relationship between the Moon Cell and the Crimson Moon? Does the Moon Cell exist in universes outside of EXTRA?
A: Moon cell is something that is only in EXTRA, and it does not have anything to do with the Crimson Moon. However, in the world of EXTRA, the "Brain of the Planet" (Archetype Earth's title) who is equivalent to the Crimson Moon should still be living somewhere.

TYPE-MOON Fes. Official Pamphlet 10th Anniversary Q & A Booklet