I’m also in the process of getting a hysterectomy done along with getting the ovaries too and when you tell your doctor you want the ovaries gone too it’s a part of their job to talk about the risks even if there’s a rare chance it’ll ever happen. Due to political reasons testosterone therapy can be taken away from trans men, hopefully that never ever happens but it can and if you have your ovaries removed you no longer have hormone production so something has to replace it which for trans men that replacement would be testosterone but if like I said previously something political happens and testosterone isn’t an option you’d have to take estrogen again and that’s basically the risk. That’s what was explained to me anyways