I mean, it's certainly possible. There would have to be medical and psychological evaluations and consultations of course.
To be clear, I have no problem whatsoever with people who meet any or all of the criteria to determine they have gender dysphoria, or who are 'officially' deemed to be transgender, and I am sure that it is an inexact science that would benefit from greater research, and those people absolutely deserve all of the rights of transitioning to a new identity and to be treated as their new identity while transitioning, and society has a lot of work to do to make obvious pain points and general shittiness (like forcing them to use 'deadname' identification) less shitty for them.
But those aren't the people who are basically fucking shit up for people who would pass any and all tests that could be adminstered, and being toxic assholes activists about it.
Its the people who just decide they are then start taking over the counter meds when they feel like it, then stopping and starting, who would not pass most evaluations and decide they know best anyway and demand the world changes to suit them.
I would imagine, but I haven't looked up the laws in countries so maybe I'm extrapolating from what I know of, that an official recognition of a sex/gender change has some administrative or court based approval system, including a psych evaluation. Pending that I doubt his request would be granted. Would he open the proper procedures, I'd imagine it would be strictly scrutinized.
Yes, that's how it currently works in most countries (that recognise trans at all) AFAIK.
But there are people pushing the ideology that it
should not be the decision of anyone except the individual concerned, and that nobody can question that individual once they decide what they want to be,
Which is absolutely ludicrous.