But that's pretty different, since normal code in that context uses immutable data structures and the channels, etc. are language features. You then don't have to tack something like Send(able) onto arbitrary types because they're immutable anyway. The whole point of Send(able) is thread safety in the face of generally mutable state in contrast to something like Concurrent Haskell.
Concurrent Haskell doesn't use typeclasses to constrain what data can be passed between threads. All data can be in Concurrent Haskell because all data is immutable anyway. It's a fundamentally different concept, not a slightly different subset like affine/linear types.
