This feels likely to me. I'm anticipating a brief "peace time" after this big trial showdown where the team is fractured by personal problems and going off in their own directions. I see Rogue being one of those who stays because she has nowhere else to go really and is the only one with any loyalty to Mags.
I can totally see Remy bowing out for a minute and trying to move on with his life, maybe in Genosha. If you think you are not needed and not wanted and no one believes you when you say Mags can't be trusted, then it tracks. Storm is his only other anchor to the team and she is also gone.
Stubbornly trying to pursue Rogue if he thinks she loves someone else who can actually give her something he can't, he'd probably see leaving as the more honorable thing to do. If he sticks around acting bitter and jealous, it's not a good look.
Also ... Rogue needs to miss him. She needs to realize what she has in him. He's been the one laying out his cards pretty plainly from go. It's her turn to pursue him and decide who she wants and what she's willing to do about it.