I've had the 'noone showing up for an event, be it a dinner/party/wedding invitations. Like always. The club events also doesn't show up with full members, that is new though. From last patch I think. But as long as at least 4-5 show up, I'm a happy camper, at least when it's not the family meeting clubs (where I sweep up all the family + those not living in household and have a reunion style club meeting).
Haven't tried the xmas tree thing because it's not Winterfest yet and...wait. Christmas trees catching on FIRE?!?! Yeah, no. Never had the fire thing.
But I have noticed that my Sims no long stick to teaching toddlers on the potty or on the play brick things. Even though the toddler asks for lessons. They stick around for a few Sim secs then go wandering off while the toddler is still on the potty/playing.