I liked them coming back too and I feel like they deserve some screen time the most.I feel like CoM created the potential for so many good-to-great ships. Riku/Namine, Riku/Repliku, Namine/Repliku. Not surprising considering it's one of the best-written in the series, it fosters your emotion for all those characters so well. I'll be honest that I was happier about Repliku and the other CoM characters being brought back over most of the other returning characters in 3, lol. I wouldn't be surprised if Repliku shows up again eventually in some way.
But if Repliku comes back, I hope it’s with a drastic design change.