It will be very good for the kids. They will know about Bitcoin, because Bitcoin will also have later a good future and that is good.
They can learn how to handle with Bitcoin and what you can do with Bitcoin and that is the best thing.
Just wondering, how would you design a Bitcoin toy? It has to be a way in which you actually get to educate the child with it. You can't just print a Bitcoin Symbol on a toy and then say it's an educational/informative toy. I for one actually don't know how I'd want to make a Bitcoin toy. It sounds complicated, but a good idea nonetheless!