> There are still implementations of the original STL around separate from the std library, so keeping the distinction is probably still wise.

As far as I am aware, those libraries are defunct and unused (e.g. STLPort), so I disagree that there is an important distinction to preserve. The most widely used C++ Standard Library implementations by far are GCC’s libstdc++, Clang/LLVM’s libc++, and MSVC’s STL. Being bundled with compilers means that there is no reason to want an implementation of the historical ancestor library.