Someone earlier asked why does it have to come down to sexuality. Because some people dislike depictions of things they are uncomfortable with, and on the other hand, we LGBTQ+ like to be acknowledged as existing.
Someone also said they thought heterosexual was a term being shied away from. I can't recall that ever being commonly used, and even straight is mostly just mentioned when being not gay. In fact, I would say it's always been the least mentioned identity because it is assumed to be default. Straight characters are not in danger of disappearing. What is hopefully disappearing is the idea that people need to define themselves into slots and then justify any divergence from that slot. For example, I found it annoying when Stamets identified as gay on Discovery because it's needlessly limiting of his identity. It doesn't make sense to me in the confines of the world he lives in. However, I know that it really matters to some that he does identify as something, and to say gay in Star Trek is a step forward.