The fact the number of people picking random pronouns is very small, is no justification for everyone else having to put their chosen pronouns in the email signatures.
But by all means, feel free to give me evidence otherwise.
What is wrong with just people who for some reason get paranoid of a pronoun used for them that might be wrong, which they will never know as they aren't present, just doing the signature thing (opt-in) and I and every other person will try to do it, if we remember, while leaving everyone else to live their lives doing things that are actually important?