Didn’t contact anyone. But you can find this page.
Also AntC2 wrote this week in his post:
“As at 2010, all Haskell compilers supported extensions beyond the 2010 standard – there just wasn’t enough agreement about which extensions were ‘standard enough’.”
I think for Haskell’s acceptance it would be more important to stick to a standard over a longer period than everyone trying to achieve the perfect language. If there’s a consensus in the group, fine, then you can extend the language. If not, leave it outside. Benefit of this: Standard keeps small.
By the way: The reason that “ugly C” (like some say) is so widely adopted in the industry is their standard, which you have a lot of compilers for. As a commercial user you need alternative solutions if something goes wrong.