I’m by no means an expert in Web Assembly, but this probably wont remove the need for wrappers.
A library like Bootstrap’s JS or framework like React will probably not be compiled to Web Assembly in such a way that other languages compiled to Web Assembly can use them in the way they were intended, and that one can look up in their documentation. Instead you will have something akin to external/dynamic. That is my guess anyway. - Even interop with C++ from C ruins any beauty of a C++ library.
Good typed wrappers are needed. TypeScript has a bunch of good typed wrappers. ts2kt tries to exploit that but is not quite there yet.