I have never heard anything about George Lucas mandating that Bioware cannot include same-sex romances in SWTOR. I would like to see a reputable source indicating that, especially seeing as Bioware has released an official statement confirming that same-sex romance choices will be included
in SWTOR as a post-launch feature.
Google "same sex swtor" and the official statement is the first result.
My best speculation would be that there was either ratings-related pressure from EA or, more likely, that they simply did not have the time or resources necessary to allocate to voice acting for all of the same-sex pairings. Considering this game has been in development for many years and is one of the most (if not the most?) expensive video games in history, my money would be on this being the case.
I myself am only interested in same-sex relationships. The fact that same-sex romance choices with NPCs will be included post launch does not upset or offend me. Besides, it will be vastly more enjoyable to have my Bounty Hunter collect a handful of corruptible little Sith Inquisitor and Sith Warrior
... err ... players
to satisfy those ... needs.
Mm. Maybe I should go post an RP Request, now.