It may be linguistically fashionable to use ‘they’ and ‘them’ as gender-neutral singular pronouns, e.g. ‘Every teacher in that school is given the autonomy to use the curriculum as they see fit’, but I am still going to be pedantic and deplore its use.
It is insulting and offensive to logic to substitute a plural pronoun for a singular subject.
If ‘he or she’ is perceived as too clumsy, use ‘he’. The male pronoun has traditionally been the gender-neutral pronoun of choice.
No one except mad feminists would mind the usage.