We can barely even meaningfully define UPFs, and they aren't cleanly correlated with junk food.
Potato Chips are not UPFs but tortillas with an added preservative are.
Ice cream purchased at the store that has emulsifiers is a UPF. Homemade ice cream is not. But I think we'd agree that it is the fat and sugar in the ice cream that is the bad part to feed to kids.
I will go further and say that eating some ice cream does not hurt kids at all. No, you are not a bad parent because you gave your kid ice cream. And fat is completely legitimate part of food. Likewise sacharides.
Potato Chips are not UPFs but tortillas with an added preservative are.
Ice cream purchased at the store that has emulsifiers is a UPF. Homemade ice cream is not. But I think we'd agree that it is the fat and sugar in the ice cream that is the bad part to feed to kids.