Sure, in terms of underlying functionality WASM or even plain Js can do everything Flash did. What I'm talking about is lack of tooling and accessibility for non technical people to create content. Macromedia Flash was a really easy to use tool that anybody could quickly get started with and make something. You didn't have to have any programming knowledge at all. Maybe we'll see newbie friendly tools built on top of WASM someday, but currently there's really not much happening in this space.