Who knows... eventually with a path from LLVM to webassembly... or something similar...
If it already runs on the iPad, doesn't that mean that "all" dependencies on "strange" libraries were "resolved"? If so, the sky is the limit!
(hope should never die)
PS - here that no one is listening, it is the "WL" that we want to run on the browser... not "Mathematica" ;-)