That is never going to happen.
This is a constant theme on Reddit at r/programming. It is based upon nothing but fear of web technologies (yes, I literally mean fear as a raw and savage emotion) and a lack of understanding what WASM is. It is best to think of WASM as an embeddedable VM for JavaScript rather than opposed to JavaScript. https://webassembly.org/
First of all JS cannot ever be replaced by WASM. This is a stated project design goal of WASM. You have to understand that Web Assembly is there to fill the proprietary application add-in void of things like Flash using open standards safely in a way that is technology agnostic. Web Assembly is not there to serve as a crutch for people afraid of web technologies.
Secondly, there will never be direct DOM access from WebAssembly for security reasons. While that is the nail in the coffin on this matter there is the more practical consideration that developers, even those who write JavaScript full time for a living, tend to be deathly afraid of touching the DOM. If this were a reality the inevitable overhead (think of all the dependencies, frameworks, and abstractions developers cannot live without because the DOM is scary) would likely be just as high, or higher, than writing your own DOM library embedded within your WARM instance.
Thirdly, you can have a DOM interface in a WASM instance. This is part of the web components API, but DOM trees created for the WASM instances are islands to the WASM instance created from external JavaScript - https://medium.com/coinmonks/develop-w3c-web-components-with...