Sometimes it's more about re assuring the kids.
I don't have ex DH, however was a child of separation, and often found that dad/mum would send us with things because they though the other would forget, but overall it meant us kids could still enjoy things without having to build resentment toward the parents because they were slack. We were kids we didn't and shouldn't have to worry about that stuff.
I would sent them but perhaps if one of your kids is old enough suggest to them to suggest to ex to buy us just like this so they won't forget and miss out on fun!