Unless talking about your personal life is a punishable offense at your company, there is probably nothing that you can do about this.

This sounds like venting as opposed to a focused question. My question back is why you waited/listened to (and thus, legitimized) their speech for 30 minutes before intervening: "Hi, excuse me -- I appreciate you sharing, but I don't think this is the best time or place for this type of conversation. Please see me before you go on any further, so we can figure out the best way to share this information with the team." Then you tell them you would have appreciated a heads up and come up with a better plan for communicating. Best option now is to check with higher-ups how to handle. Good luck!

Why did you let them call a meeting and tell people off, that seems very bad for morale.

@TymoteuszPaul She/he did say they were going to transition, but didnt yet tell me if they prefer to be treated by they/them or He/Him

@A.S I don't have the authority to do that, and I didn't want to seem that I was against the transition per se, because that's the focus, I was also astonished by the guts He/she had in order to do it, I was flabbergasted for lack of words. Also the higher ups left the decision up to me and shes a good programmer.

@Or4ng3h4t then call them by their name or they, this is extremely jarring, and probably insulting.

@TymoteuszPaul I will edit to reflect that, I didn't think this could be insulting, since some people do use both.

@Kilisi It was following the revelation X was going to have surgery.

Thanks for that, and yeah unless someone explicitly told me "i want you to call me both at the same time" I would not assume so, and even then this would raise my eyebrows. I may post answer later, mulling over it, but as you want to keep that person, you rally need to get a lot more sensitive and accepting of their choices and help them navigate it in the workplace. If that's not something you can realisticly do, I don't think it's likely you can keep them.

@Or4ng3h4t so? What difference does that make? Coworkers ranting about anything is bad for morale.. You should have shut it down straight away and sent them to HR to rant all they want

@TymoteuszPaul I'm already enrolled in sensitive training, I know this is an issue and I have been trying to get It under control (my SE timeouts speak for themselvs). I might never agree with X, but I damn sure will respect his opinion and right to do what ever X wants to do with X's body.

@Kilisi I know, but I can't, we dont have an HR department, every team leader is responsible for handling this type of stuff, I Ducked up due to being shocked. I can't go back, I just want to help X stay and have a great career.

@Or4ng3h4t then perhaps you're the problem that needs to go? You want to protect something that is bad for morale and allow unprofessional behaviour to impact your whole team. As a manager you have a whole team to look after, you don't pick and choose individuals over that.

@Kilisi Perhaps indeed. I like to think everyone deserves a second chance. My Team is taken care of, they just spend too much time making fun of X and the details she shared. They aren't right too, if I fired X I would need to fire my whole team for being unprofessional and discussing the private life of X.

@Or4ng3h4t yep, you ducked up once, now you have a second chance. Probably not what you meant but it's reality. However I'll edit my answer to give another option.

@Kilisi I value your opinion, i've seen you arround.

@Or4ng3h4t thanks, but don't overvalue it, I'm not infallible, plenty of intelligent and experienced people here. We don't have the whole gender obsession thing in my locale, so I'm just answering from the professional role angle.

I'll never understand why colleagues think we're interested in their bedroom activities - keep your private life private we dont care. Rant over.

Please don't refer to people as "it" (second-to-last paragraph). Since this question could be generalized to apply no matter what the person's pronouns actually are, I suggest you choose one (he or she or they or ze or ...) and stick with it.

For all of you assuming the proper pronouns for employee X and making OP's lack of stating a pronoun an issue -- how do you even know that the conversation was in English, as both are in Portugal??? How can you assume that the pronoun you think is the correct one is the same one that employee X would want to use? Do you see yourselves right now? "Triggered for the sake of being triggered"?