Bethel and Hazelwood have subsequently and substantially (IMO) watered down Tinker, however . . .
Yep, I agree. Nevertheless, the rationale is still that the (public) school has to have a valid educational purpose for practicing censorship, not that 'minors' don't enjoy Constitutional protection at all. It's the latter view that I've been surprised to encounter on this forum.
True enough, but unfortunately, I think it's going to be tough to fit this into even the limited rights students enjoy.