Problem there is, we have all the original companions straight, the new ones Bisexual....
Where are the Gay and Lesbian characters?
There are existing companions who are currently unavailable for opposite-gender romances, despite being what you might call suitable. I would imagine some of those will be your same-sex only options. For example, Talos Drellik is not available to female Sith Inquisitors, despite being human and (seemingly) rather keen on his boss. He's one of the companions I suspect will be SGRA-only when it's patched in.
On the subject of bisexual companions, I think it would be nice to have some who are. I'm not for a moment suggesting that all companions available for SGRA in the future should be, but some representation would be appreciated.