I think that Haskell2010 could be the last Haskell standard. Modern Haskell has diverged to such a degree that it seems to be (almost) impossible to define a common standard. Even if they would, as long as there a over 100 language extension (increasing over time) there will be developers using them. Take a look at C++20, I think it's obvious that C++ is beyond repair at this point in time, even if you wouldn't add any more language features.

Sure, a new Haskell standard would allow for more compiler competition and that's a good thing, but it cannot fix the language. I think what we really need is a new language that picks all the good parts from Haskell, but has a very small syntactical core. Something like Go, but purely functional. You might say Rust or Elm. But Rust is too performance oriented and already quite big, hence more like a C++ replacement. And Elm is too domain specific and maybe a bit too simple (lacks ad-hoc polymorphism).

So maybe a general purpose Elm like language with ad-hoc polymorphism, but not as complex as Purescript, with a GC that compiles to binaries and WASM with a standard code formatter and very conservative regarding new language features, just like Golang.