Very very little content in this game is gated by pronouns, none of which (so far) is marriage.was gywn made unmarriageable because gender requirements
I don't know that Tobs and Savin ever had marriage planned for Gwyn. I also don't know that they're going to take it off the table. We'll see what happens.
The only characters that explicitly have had marriage planned for them are Atani, Ahmri, Kiyoko (already in the game), Etheryn, Carmen, Kythie, Brint, Brienne, Rina, and Cassia (in varying levels of development). The only characters that have had marriage ruled out are the concubine floofs, Miko and Rindo. All of those plans are subject to change - it ain't in until it's in - and the number could very well expand.