This custom is catching up also in Germany, probably influenced by American films the kids see: at least in the two places I have lived in the past several years (Eastern, not very "hype" or full of Americans: Alt
Treptow and a Plattenbau area in F'Hain) there have been kids (not every 3 minutes, but at least 2-3 times during the evening) coming up. Last year I think I saw even that the local children club (or whatever you call those neighbourhood afternoon activity clubs in Germany), has organised a collective ToT.
Some of the older "Ossi" neighbours here seem not to understand (but since the grannies here seem to be stereotypical German grannies, who always have *something* for kids at home, they give them candies anyways); For me, as a non-American (who doesn't anxiously wait and remember Halloween in any case), it is always the other way round: "*&^%! Have I forgotten (again) to buy sweets for today? Should I be the nasty auntie that gives them some health stuff instead?"
By the way, not being American I have no idea how to compare traditions (certainly the one here pales in comparison to the US/Canada) but I have yet to encounter a kid saying something else than sorry if the person tells them that they have no idea what they're about/haven't any sweets.