Honestly I don't see how a low-level paradigm takes over a field when every other trend is towards ever more abstraction. Sure, wasm has its rightful place, like DX12/Vulkan, but it's a tiny fraction of apps/projects. Most likely we'll see js-to-wasm preprocessors of sorts to invoke optimized calls when it matters, but most devs won't touch low level (much like most game devs don't touch engines/middleware).
There's the 1% edgy companies built on node+rust/D and what-have-you, and then there's the 80% wordpress crowd who longs for a human-readable programming language a la Star Trek. I think the latter is a future that will come unimpededly over this century, as far as the majority of the industry is concerned.
More pressingly, people are waiting for async and other cool multi-threaded features in JS, and ES6 really is a second coming of sorts in that regard. Long gone are the days of horrendous paradigms once we adopt the 2016 spec, really.
Economically, because that's the true judge ultimately, we have to consider the existing JS ecosystem: actual prods, skillsets, experience, actual needs of businesses who fund the construction of the web currently solved by JS, and so on and so forth. It's a giant thing, that JS. If we had a better alternative today, we'd still be writing JS in many projects in 2020 and maintaining some of it late into that decade. Let's face it, JS is here to stay, there's no turning back now --see how polarizing Java has always been for another historical case, and see how it's still top 3: can't suddenly undo all that cash poured into production, can't instantly retrain hordes of programmers.
I'll say one thing about wasm though: it's a formidable effort that paves the way towards a truly 'next-gen' web paradigm, most notably suited to be actuated (viewed) within a VR/AR environment; it's also a prime candidate to run on the smallest devices at the heart of an "ambient"/IoT ecosystem. I'm considering a superset of low-level networking protocols that go beyond the web, obviously. And I haven't researched anything about it yet but I suspect the low-level hooks of wasm could be hacked to do some fancy ML stuff on-the-spot (thinking low-cost online algos and reinforcement learning here, if we are to make our 'ambient' IoT ecosystem able to 'learn' about us as users and map the physical world semantically).
Ha, fascinating times, really. Let's just not lose sight of how the real world operates, though, if only to improve on that. In due time when ideas become feasible under the right circumstances. Low-level programming is very much not how we've trained the bulk of tech people since the smartphone era / mobile paradigm essentially. It'll take time to shift, if we ever did. I don't think we will, in the grander scheme of things.