Can they do it? Yes. Can they do it with a reasonable level of support for many different desktop hardware so it’s cheap to implement? Probably, though it won’t be as comprehensive as windows. Can they get a 1:1 replacement for windows that has the same level of security as windows? No, because many national governments collaborate on windows security. But! They’ll be safe-ish from NSA back doors in windows (if you think there are any)
Can they do it? Yes. Can they do it with a reasonable level of support for many different desktop hardware so it’s cheap to implement? Probably, though it won’t be as comprehensive as windows. Can they get a 1:1 replacement for windows that has the same level of security as windows? No, because many national governments collaborate on windows security. But! They’ll be safe-ish from NSA back doors in windows (if you think there are any)
Many national governments collaborate on Linux security as well.