I agree that the term is mostly used to bully people. But to be fair, you're inventing your own definition for the word.
The definition you're using:
male socialization (n): the cultural conditioning produced by a patriarchal society
The standard definition:
male socialization (n): the cultural conditioning applied to those in society assigned male at birth
As far as usefulness, it does have actual positive use even in the trans community. Sure, some portion of the trans community doesn't care about passing, but most do. And if you're a binary trans person actually trying to be seen and treated by strangers as your gender, adjusting your behavior is part of this. Cis society expects men and women to behave differently. Boys and girls are raised differently to reflect this behavior.
And for a lot of trans people, a bit of deconstructing of their own male or female socialization is necessary if they want to integrate into a binary role in society. Even just simple things like how men are conditioned to take up space, while women are conditioned to take up less space. If you're a trans woman and you seek to blend into society, if you don't work on some of your male socialized behaviors, you're likely not going to be able to pass. Sure, some trans people just completely reject the socialization forced upon us, but most of us don't. Most of us absorbed a lot of our gendered socialization growing up as a survival mechanism. And for most trans people, deconstructing that socialization is part of transition.