Like cash it doesnt really teach kids even some adults about how to properly manage spending. It really depends on the person using bitcoin, it also depends on the people around that person or kinds who will teach and remind them about handling and managing their bitcoin. If we will teach kids about proper way of spending and saving its better to show them how to do it not just by words but also by example.
We do not need money to teach about kids about saving, you could use candy, you could give to them some candy and tell them that if they keep that candy for some days that they are going to receive more candy in return then you explain to them the same happens to money and bitcoin and they are going to be able to grasp the concept immediately and understand the concept of saving.
This is perfect example of how some people give bitcoin to much power. Many similar threads where people think that bitcoin can solve poverty, bitcoin can solve all the problems in economy, and now we have thread about bitcoin helping kids to save?! Bitcoin can`t help in any of this things, bitcoin doesn`t have power to solve anything, its a tool, and tools are used to make things easier and better but only if you know how to use it.
You can give many examples how to teach kids about saving, probably all of them are good, kids are different and each kid needs different approach. When you teach him how to save he will save everything, not just money.