I was so dissapointed with absence of any comments from my companions after the revelations from Gortash. But as mentioned above, apparently there are some reactions... which I did not get. So I guess... bug it is.
But beside this I still had a feeling, that nobody actually cared much about the whole urge stuff. The first meeting with Orin (before the bhalspawn revelation) when she called the MC a sibling I was really expecting some 'WTF'?' from the companions, but nobody said anything. Maybe another bug? Who knows...
In general, the idea of bhalspawn has a potencial, but I think it is still lacking, when it comes to companions reactions.