Uhh, yeah, that's exactly what he says he's going to do. He'll use whatever pronoun you look like, but if he finds out you're trans, then he's going to make sure to use the one that is likely to upset you somehow. Maybe it offends someone, maybe it doesn't. But he's putting in effort to do something that might, instead of acting how he normally acts and doing something that won't. You don't have to buy into absolutely every ridiculous thing the extreme woke crowd is trying to sell to simply not care what pronouns you use. Putting forth minimal effort not to do things that might upset folk is a good thing.
For instance, sometimes I have dinner with my folks who are Christians, but I don't believe in god(s). They stop to pray before meals, so I sit there quietly and wait for them. Simply because I don't believe in god(s), you're saying it would be just fine and dandy for me to start talking and eating and telling them I don't believe in their fairy tales?
And a side note, let's get this out of the way because I saw you already comment on it earlier.
I am atheist because I do not believe there is a god.
I am not thus required to hold the belief that there is no god.
I am hard-agnostic because I believe it is impossible to ever know if there is a god. (A soft-agnostic would simply say that no one does know if there is a god)
I know you Christians hate atheist/agnostic used that way, but that's the way it is. I'm not going to argue with you over it.