Indeed - Lemmy integrates well with Matrix and there’s no reason that can’t be done here as the main issue would be the security of the messages exchanged.
The other bonus is open and clear matching algorithms. It’s in the interest of commercial dating apps to keep the majority of their users always hopefully but never quite there (or they’d run out of business, so, ironically, they’re business model relies on not being successful) and I suspect they use some shifty practices in the matching algorithms.