That is polite of them not to be offended. My wife has LBGTQ among her Women's Health patients and they aren't offended when she messes up a pronoun. But they're very appreciative when she uses the correct one and respects their choices - it's professional and personal courtesy.The ironic thing is everyone I’ve met who is in one of these groups that “needs to be protected from harmful speech” doesn’t give a crap. Ask someone adopted by a same-sex couple if they get offended by the generalization that the vast, vast majority of people have a mom and a dad, and you’ll most likely get a resounding no. Most of this is just contrived virtue signaling.
Same goes with a few people I interact with at work - they aren't upset.
But that doesn't mean we should ignore people's choices and call them whatever we feel comfortable with based on our own beliefs. People should be respectful of others' choices and teaching cadets to make the effort to be courteous, respectful, and professional makes sense.
This reminds me of a thread here or elsewhere a while back about young enlisted guys not calling female officers ma'am because they didn't think women should be officers. I believe the consensus was that those enlisted should have the riot act read to them.