You know, if we take our expectations off and try to view our followers as actual people in a world with their own personalities, own idiosyncrasies and own quirk, we would see that it does not make any sense for them to have love and romantic choices that caters to us or rather, caters to the Inquisitor's whim. It would not make sense for them to be equal since they are their own characters, not just Inquisitor's playthings.
Before anyone comes and labels me as homophobe or anti-equalist or whatever labels they want to, my planned default Inquisitor is a male Dalish elf mage who will be a bachelor. So I really have no reason to spew BS.
Which means I am not saying this out of spite or hatred, I am saying this because this is the direction Bioware wants to take their characters. They want to make them their own person as opposed to completely subscribing to a trope or an ideology. A person almost always has a mix of tropes they identify with or that others identify with.
In case of Solas, he seems to be an introverted and intellectual elf. However, this does not preclude the possibility of him being open minded intellectually does not mean he has an open view towards sexuality. That is neither a bad thing nor a good thing, its just his thing. Its Solas' thing.
As for the last romance option, it would most likely be Vivienne and she will be gated towards male only. Not because of lack of equality but because that is Vivienne and that is what she is. From Vivienne's drive to be ambitious and climb up the political ladder, it makes sense that she pick the human noble man as a love interest because they can help her further her political goals.
Cheers.