Something like that?
“The x is intended to stand as a wildcard character“ https://en.m.wikipedia.org/wiki/Mx_(title)
Meaning not exactly the same, but closest relevant title.
Here is Webster's Dictionary where they agree they are nouns
Just with the simple trans stuff, estimates are about 0.5% of people fit that description. So about 11,500 employees. Not all of them are fully out, so you're looking at a lot of people that don't fit that bill.
Some people really do not want to be a Mr. or a Ms./Mrs. I think it goes back to bad childhoods.
Some people really do not think that they are a Mr./Mrs. anymore, that they are Dr. or Col. or Rev. now and just reject the Mr./Mz. out of hand.
I have older people in my life that are super particular about the Mrs. thing and just use Mz. and always have.
Also, you still have a lot of women, especially older and in the south, that will take their husband's name as their formal title (Mrs. Dr. John Q. Doe). And those that I've met that do this are very particular about it.
Again, there's a lot of people here and I think leaving it up to the particular person on the other end of the conversation is the only workable method. It's a 2-way street afterall and you have to respect that other human on the other end.
In the very least, you've gotten a lot of info about them and their personality that you can then use to your advantage.
People should do what they want with pronouns in email signatures. But I don’t understand why you can’t string these together.
"Mr. Doe is my father. Call me John"
And yes, even the 70 year olds still do this around me, and yes, I find it really weird too.
Vietnamese names are gendered but Westerners have no idea which genders go with which names. (Is Duy male or female? How about Duyen?) So, at least in my experience, they've always just put Mr/Ms in their email so people know which it is.