This is a common tactic of modern bigotry movements: claiming that it's the people they're discriminating against who are "the real bigots". The "I know you are, but what am I?" approach, as it were. For transphobes, who've spent the last few years trying to claim their bigotry is, somehow, 'protecting women and girls' (despite all evidence to the contrary, the amount of open misogynists and anti-feminists who've jumped on the transphobia bandwagon with no difficulty, etc.), this means that people who take issue with it can be called misogynists.
How much any of them actually believe it, versus how much of it is a PR gimmick or just something to troll people who disgree with them, is anyone's guess, but it doesn't really make much difference in terms of how they act and in all cases anyone doing it is just not worth engaging with.