tbh, at this point I'm kind of still wrapping my head around the direction PM took with their Cathy, but for now I'll say what I think is best for Heathcliff, which is that I hope he gets move on and rebuild his own identity outside of his tie to Cathy. All the Cathys have been cleared from every single mirror world, so them reuniting is unlikely- unless 'our' Cathy lives on in Dante's ipad or something, in which case maybe her consciousness can be booted up into a bot à la sephira from LC/LoR? Who knows!