Linux and open source are the future and there is no doubt about that, to see this come to a reality, a strong foundation has to be laid, by starting from the lowest level possible and that is exposing kids to Linux and teaching them how to use Linux operating systems.
Linux is a very powerful operating system, and that is one of the reasons why it powers a lot of servers on the Internet. Though there have been concerns about its user-friendliness, which has brought about the debate of how it will overtake Mac OSX and Windows on desktop computers, I think users need to accept Linux as it is to realize its real power.
Why Linux specifically? One thing common to children is curiosity, and early learning can help instil a character of exploration in them when the learning environment is designed to suit their needs. Linux is all about curiosity, experimentation, learning how it works, adaptability and customisation.
See https://www.tecmint.com/best-linux-distributions-for-kids/