She made a suggested change to the uniform.
Your husband said "Not likely to happen".
No, he said that he didn't think it would be wanted by many people.
He also never said that this person wasn't allowed to do this for themselves. I don't think many people have a particular issue if individuals want to do this, but most of them don't seem to be happy with this - they expect everybody to be encouraged/forced/shamed into following suit - and the vast majority of people, who will identify by default with the pronouns that you'd 100% expect, simply don't care about this as something for themselves.
They view it pretty much like an ardent football fan who isn't just content to go out in public wearing their beloved Chelsea shirt, but will also demand of everybody they meet - regardless of whether they are football fanatics, quite enjoy the game, have no real interest or actively hate it - to declare whom they support, and then be expected to justify their reason for this, when if challenged.
Most people just want to go to work, do their job and get paid for it - they don't want to be made to politicise being an accountant, cleaner, teacher, shop assistant or whatever (fair enough if their job is a brand/belief ambassador).