Everybody else will act normal and all prior evidence of their existence will also persist like normal.
I guess for most people it would be pretty much immediately if their significant other isn’t there in the morning and for some fringe isolated cases it might take forever.
I guess best case for me would be around 4 hours on a work day during lunch break seeing a big crowd of people when it would finally click.
Worst case would be probably 5 days when I’m mostly working from home office.
What happens to intersex people?
They go in a quantum state, existing and not-existing at the same time until someone perceives them, at which point they go into one of the two quantum superpositions: being or not being.
Or nothing would happen, idfk.
Intersex people don’t vanish. If you yourself are intersex, nobody vanishes for you. Trans People vanish based on their passability for the opposite sex, if they’re androgynous they don’t vanish. If you yourself are trans then the opposite of your prefered gender vanishes.