And even when someone has known preferred pronouns, is using gender neutral language problematic anyway? I can understand people being upset by others using ge

And even when someone has known preferred pronouns, is using gender neutral language problematic anyway? I can understand people being upset by others using gendered pronouns that are not aligned with their own gender identity, but are there any people who've declared a preference for "she" or "he" or anything else, who'd be upset of offended by the use of "they"? (I quite often stop and rewrite a sentence when posting places where, I don't know the readers well enough to know their prefered pronouns, and my usual approach is to reword using "they"...)