One obscure compiler is known to have implemented some of these features, but it wasn't available for testing firsthand, test code was sent to someone with access to it who reported the results.
Even now I don't think there are more than two implementations of any of those features. Template aliases are another feature with very little implementation experience.
As for the library, I've done a partial implementation of the new allocator model and added support to a single container, but there was no full implementation available when the allocator changes were added to the spec. Noone had implemented 'noexcept' throughout the standard library when those changes were made to the spec.