This is patently absurd. I'm neither trans nor religious but hypothetically I'd much rather announce that I joined a religion anywhere in the US than announce being trans in the small town where my grandparents live today. Let alone Alabama 50 years ago.
Yes in very progressive environments you will get more support for announcing the later but that's because being in the later group is actually a challenge while religion has built up a reputation for maligning groups of people for things out of their control and for generally anti-scientific beliefs. Being part of a group that largely denies evolution and climate change is obviously not going to grant you any favors in groups with an academic (especially STEM) background.
Yes in very progressive environments you will get more support for announcing the later but that's because being in the later group is actually a challenge while religion has built up a reputation for maligning groups of people for things out of their control and for generally anti-scientific beliefs. Being part of a group that largely denies evolution and climate change is obviously not going to grant you any favors in groups with an academic (especially STEM) background.