Not in every circumstance, no. And, of course, everyone is entitled to object to something they feel strongly about. Again, some objections can veer into transphobic territory.
So in some circumstances, it is and in others, it is not? I don't understand the difference. Can you explain, please?
For example (and this is very simplistic of course), the objection to sharing a space with a transgender woman because of a belief that a transgender woman is more likely to enjoy indecently and inappropriately exposing themselves (eg, a 'flasher').
So, if I object to sharing any such public space with any individual with a penis under any circumstances does that make me transphobic?