Yeah, I spotted "They know my kid is out and still treat them well, but they use my kid’s old pronouns" and ABSOLUTELY SAW RED, but I guess there's a faint possibility that said kid is okay with it. I suspect, given that it deserved a mention, that their kid DOES prefer certain pronouns, and the grandparents have chosen not to respect them.

(Even if the kid said "Eh, I guess it's not a battle that's worth fighting," I think it's a matter of basic respect and consideration to use the pronouns that people use to self-identify -- the fact that the parents/grandparents are making it too difficult to be worth the fight doesn't mean that it's not a constant microaggression.)