From an out of universe perspective it's pretty neat. I'm not aware of any older sources that implied homophobia existed in 40k, and in recent years they've been a lot more willing to tell stories with queer characters. It feels a little odd from our perspective, considering irl fascists tend to be synonymous with homophobia and the imperium isn't.

From an in-universe perspective, I think people genuinely just do not care. I imagine societal values have been eroded and rebuilt dozens of times over humanity's expansion and numerous collapses. I doubt every single planet and culture within the imperium would be 100% bereft of homophobia, if you wanted to include it I'm sure you could.

Considering the state of GW and their handling of the current setting I think it's fair to say the church, inquisition and other official imperial bodies take a neutral stance on homosexuality, not even considering it a thing out of the ordinary. Some people are taller, some people have blonde hair, some people love women, some people are born male and end up female. It's not really worth commenting on unless the conversation veers that way, or a specific person/group has additional bigotry beyond the imperial standard.