I think it’s incredibly sad that we even need to study this. It’s pretty obvious just from looking at cis men. Take almost any cis dude that has a condition that gives him enormous bojongohongos and he’ll be way happier with a breast reduction surgery. This is incredibly obvious to even transphobes.
So, a trans man with huge gongabadongos is obviously going to be way happier after a breast reduction surgery too. And hormones also have physical effects. Most guys like to have deep voices and facial hair. Not all, but most. So why wouldn’t a trans man?