For the sake of this discussion about romances, I didn't include Varric. And again, audio files have been found suggesting that Solas was also supposed to be a bisexual romance.
Right, but that's the difference. Removing Sera's lesbian sexuality does have implications beyond just the romance content. That was my point in differentiating between Cullen and Sera. For Cullen, because there are already several other straight guys, the 'effect' remains within the romance content. With Sera, it means that lesbians are removed from the inner circle altogether.
Well it wouldn't REALLY matter if he was, but it would be cool to introduce a Rivainni prince/Templar, you know some more minority for your minority. Lol
I'd be down. Ser Barris...... 
That being said, they've done a good job with this in the m/m romance option pool.
Sky, Kaidan, Steve, and Dorian were all human PoCs. Iron Bull, Zev, and Fenris are non-humans. The only white human m/m option is Anders. Ugh. Anders...