I think it's fair to assume there is some cultural crossover between the corporate entities involved, but the leadership responsible for this horrible treatment wasn't involved with the development of starfield and worked on other titles published by zenimax. The hr could be the same, but as noted by others, they're just a tool for leadership. Treatment of trans people I imagine is probably highly variable in the corporate world, based on my experiences with leaders. The application of corporate rules is highly subjective and can be used to stealthily punish people the leader doesn't like. There really isn't a lot of vetting at all for leaders who are sensitive to trans issues, or anything trans really. Especially in technology. Misogyny itself is a huge issue that varies wildly from team to team (which is mostly what I've witnessed first hand). Pronouns are not even a universal thing in internal corporate comms yet.

Anyway this probably just all comes across as starfield fan cope and it probably is that but I just wanted to highlight that starfield bazingas like myself will probably look at this and convince ourselves that this is because zenimax sucks and not the Bethesda devs that made starfield. Or maybe not and I'm just a space sim sicko.
I love my trans comrades!