Joseph- honestly, it hasn’t really come up in a very long time so I haven’t really thought about it. I wonder if it’s a problem but I assume not because a glass of kiddush wine is not something the authorities care about. I guess you could make the same argument for Purim as many have here.
But it seems like at the very least you admit that there’s no halachic reason to serve them wine when they are not partaking in your seudah and when they will have a seudah on your own. Considering the possibility that kids can abuse alcohol (and unfortunately we see that they do especially on Purim), then what’s the point?