Capcom may not be able to do it, but modder FluffyQuack apparently can. A trainer (wow, haven’t seen that term in a long time) for the PC version of Resident Evil: Revelations 2 has added offline splitscreen co-op to the game, among other changes.
Both players will need to use gamepads, and Raid mode co-op doesn’t work yet, but has been promised by Capcom officially. They don’t plan to release an official campaign co-op mod, but the ease at which it has been created by the community may change their minds on an official update.
Resident Evil: Revelations 2 is available now for PC, Xbox One, PS4, Xbox 360 and PS3.