Except that the 3's aren't even. Straight guys can't romance Cullen or Solas, so it's not even.
Right now:
Straight Male - Cass and Josephine
Straight Female - Cullen, Solas, and Iron Bull
Gay Male - Dorian and Iron Bull
Gay Female - Sera and Josephine
So, it's not even and it can't be given that there's only one LI to be revealed. Don't get me wrong, I'm fine with it being slightly uneven, but I don't see why people think that this means that it has to be either a straight or gay Vivienne.
I think Gaider said that if people think that the remaining two LI were the race gated ones, they would be wrong. Meaning that one of the already revealed female LI are race gated.
There could be another race-gated male. Especially if the last LI is Blackwall.