Docker-like containers will likely exists as long as there linux servers, maybe the trendiness will leave them behind, but they are a plainly good technology to deploy and distribute application with many fantastic usecases.

I too do see a future where Wasm is way more widespread but as of now we are deploying a small app with a MySQL in single docker container. I suspect that we won't be running MySQL compiled to a Wasm container anytime soon*

* I suspect that we could with the right transpilations/interpreters but for sure we won't