How to talk to 5yo DS about non-binary / trans teacher

[NorthernLoon]

DS is in reception. We received a message from the school recently advising that one of his teachers was leaving, and welcoming that teacher's replacement. The new teacher's title is "Mx" which Google tells me is a non-gendered title. So far so good.
Today DS met the new teacher for the first time and has come home saying the teacher "looks a bit like a woman, but not really, and has a man's voice". He didn't ask any specific questions about that, so I didn't offer any explanation. (And I'm aware I might be jumping to the wrong conclusion - could just be a slightly masculine looking woman with a 40-a-day habit for all I know!)
But assuming the teacher is a TW, how do I talk about that with a 5yo?! I don't want him to get in trouble at school. But I'm not happy to teach him a belief system i don't agree with.
He knows basic male/female anatomy, the correct names for private parts, and that he is a boy because he has a male body. He's gone through various sparkly/pink phases, and my sister is a fairly tomboyish PE teacher. So we've talked in very basic terms about social stereotypes around "gender" and how they don't really mean anything.
But where do I go from here? He's a gentle little boy - he would never want to hurt anyone, and he hates getting told off. But he would absolutely go into school and say "My mum says Mx ... is really a man". And my personal beliefs aside, I don't think that's helpful for anyone.

Ships and sometimes other vessels are referred to as she. It's a kind of personification. If you're aboard a ship, you're trusting your life to it. People form emotional attachments and personify the vessel, traditionally as a woman - maybe because historically the crews were all men and boys, and statistically speaking mostly straight. Some people also personify other beloved possessions like a car or a cello. They might give them a name and corresponding pronouns. If a male acts a female part in a play one might use 'she' referring to the character, not to the actor. This might include drag queens.

However, this is very different to using different pronouns on a daily basis for a person whose sex you know.

If they said I'd like to be called 'she' but of course I'm not really a woman and will respect women's privacy and stay out of their spaces, we might have gone along. I think for a number of years a lot of us did go along.

More recently it has become obvious that that incorrect pronoun is not being taken as a polite playing along with a harmless role play, it is being taken as acquiescence with the whole lie that the person is the opposite sex. Those little pronouns are being used as a crow-bar to force entry to single sex spaces people shouldn't be in.

And that's when more and more people started saying no.

The they or made up pronouns thing is also being used to force entry (though why 'they' can't just as well use their own sex's spaces I have no idea), and it also doesn't come naturally as a role play because they (plural) aren't role playing at being someone else, they're role playing at being extra specially different from anyone else. Which is pretentious and sounds it.

Exactly this. Trans people can do what they like. But I’d prefer that my 5 year old didn’t have to learn all about an issue that has become incredibly toxic because some people feel that their voice, their problems and their victimhood trumps everyone else’s.

FFS there's no evidence this teacher is trans at all, let alone a trans woman!! Going by the title Mx would indicate either prefers not to advertise what sex they are or is a trans man. Trans women do not go by Mx!! So ridiculous

I saw your comment before it rightly got deleted

Why would anyone try to hide what sex they are?

What good purpose could there actually be to do such a thing?

Not everyone blindly goes along with something that has become toxic.. I have no issue with people presenting and dressing how they want but this isn’t the same issue as it was 15 years ago any more.

Ha that's not what your comment said and you know it

Not hide it as such, I'm just aware that some people use Mx, usually NB or trans men. I can understand why some women don't want to be called Miss or Mrs. It's just a title yet so much has been read into this, without any evidence of any wrong doing at all!

I really don’t care what your opinion of me is and I’m not going to be bothered about you scolding me either I rarely get posts deleted. But my life experiences have led me to be angry about this issue.