BA has been aware of this issue since at least 2019.
*This is only my second post so I'm not allowed to post any photos or links, so here's a copy of the BA tweet:
@British_Airways Replying to [MENTION=191333]greenlee[/MENTION]_Anne
Hi there. I've heard back from our technical team who've said: We know how important it is for all of our customers to feel comfortable and welcome no matter how they self-identify. We are working to see if we can change our booking platform to reflect this. Danny
12:25 PM · Mar 9, 2019·Verint Messaging