I think an old PC would be more useful then a chromebook to a kid interested in learning to program; also it avoids dealing with a School District IT Department, which have to defend themselves from all kinds of attack from annoying kids and parents, so are probably more technologically conservative then the average IT worker.

So my advice would be: Don't bother trying to provision a chrome-book to connect to some school network. Use a school-issued chromebook for school stuff (if that's what they issue...), use a normal PC for extracurricular learning.

For the record: my kids are in elementary school, and are issued lenovo laptops running windows. They are locked down to the point where they might as well be chromebooks; kids have unprivileged accounts and are allowed to run very few programs. This is as it should be; those computers are for a very specific purpose, and are not general purpose toys.