this is truly making a mountain out of a mole hill.
you want to know how much effort it will have taken to introduce this? the 2 normal NPCs that would be romanceable will now be coded to allow the romance dialog no matter which gender you are. that's it. the voicework will be gender neutral so it won't matter if they're talking to a male or a female. done.
they would have been doing the new voice work for the expansion regardless, now those dialog options won't be gender restricted. no extra work, no precious resources being diverted.
I don't lke the idea of changing current companions "personality"...Doc a man flirting with every woman npc's I talk with wouldn't fit....same for Trisha or Mako who is in love with another BH comp. They wouldn't fit into a SGR withouth LOT of changes. And those changes shouldn't be done.
Add whatever you want to new companions...but don't touch our current ones. We love them the way they are now.