I'm not saying anything except the series creator seems on board with it.
That final scene of them staring into each other's eyes isn't weird at all? I don't normally stare into the eyes of my friends for like 5 seconds.
and I did just power through seasons 3 and 4 after hearing about this stuff, it's not like it's completely out of left field. Korra only wrote to Asami, Asami offered to go to the south pole, etc. They didn't touch on it a lot because, well, they didn't touch on any romance stuff a whole lot after season 2's reception was as bad as it was. Wouldn't Korra and Mako vacationing to the spirit world be just as silly in a romantic context?