Short story: yesterday I asked what the date was of a school event in the class WhatsApp
From a group of 30 parents I received no response except one mum replying with the Monocle Emoji (basically suggesting I look harder for this info myself).
Long story: I'm a lone parent as my DH died suddenly just over a year ago.
Mostly I'm on top of things, but juggling everything alone on top of my grief, my DCs grief, plus health issues, covid etc has meant that occasionally I've dropped the ball by missing some school events (partly because I can't face seeing all the other happy families, partly because I'm so busy I can't fit everything in and partly because I didn't realise they were happening in the first place).
So DC1 came home last night and mentioned the school event that was upcoming, I was trying to get DC2 sorted and out the door to their after school activity, checked my emails from the school, couldn't find anything about said event and fired off question to the WhatsApp group, only to be made to feel rude/foolish for asking.
So:
YABU -you shouldn't ask questions on the class WhatsApp group to save time/energy, you should sort the info yourself.
YANBU - the class WhatsApp are designed to help parents and responding with the date would have been just as quick as the judge-y emoji response that I got.