Google is an advertising company. It would make sure there is a way to get your site indexed, perhaps by providing an alternate machine-readable version just to them. As a bonus, that version would not be available to potential competitors.

If this technique would become popular, Google will OCR it just like it runs JS.

This technique is essentially the same as websites made entirely in Flash back in the day. And back then, the only way to have Google index your site was to provide a separate (hidden) version that used normal, semantic HTML.

Googlebot runs a full web browser these days and executes javascript to a certain extent. WASM will have the same treatment if/when it becomes widespread if it doesn't already.

They can use it only for video players that'll autoplay for example.