Bitcoin as a core subject? Well in my opinion I would say cryptography as a core subject rather. Then students or pupils will be able to get a proper understanding of how the crypto space works especially in the case of Bitcoin. For some time now some schools already offer such subjects to their students however most of the time as a branch under one of their networking or programming subjects.

although it's a nice idea, the biggest limitation is the Government since in some countries , crypto is regarded as illegal therefore schools in such regions can either not teach such subjects effective or can't even teach it at all depending on the crypto tolerance of the countries government.