As a member of the LGBT community, I used to be very much against the whole "playersexual" thing. I was of the opinion that it implied that sexual orientation is not an important enough part of one's character to be fixed, but honestly... these days it seems like the preferable option to me. I came to like having the option quite a bit, and I think I finally came to understand the justification for it. It's not as though the characters actually suffered for it, from a writing perspective. Anders and Isabela had obviously had same-sex experiences in the past (and I think that both of them could easily have been considered "gay, swinging toward bi for pleasure or love"). They almost certainly would have been bi anyway. With Merrill, being curious about female romance made sense because by default, Mahariel was female--they were never romantically involved, but Merrill had strong feelings for her that were crystallized when she died. Fenris, as a character, just needed someone to love him in a real sense--I can see him being open to romance with a male simply for that reason.
Basically, in my opinion, the "playersexuality" mechanic was, in theory, somewhat offensive. In practice, though, I found it implemented quite elegantly and in a way that suited each character quite well.
As of this moment, my reaction to this news is that I'm going to be very disappointed if I can't do F/F with Cassandra. I love her more every time I see her on a screen, and I never manage to finish playthroughs with male characters. Never. I'm just not into it.