Re:We decided to go for the big rewrite
by samprotas on Friday October 04, 2019 @11:33AM
(#21158648)
https://tech.channable.com/posts/2017-02-24-how-we-secretly-...
FWIW they have this post from almost 3 years ago about adding Haskell to their stack. I'm guessing the time for your prediction has come and gone.
On the other hand, I find it quite encouraging that Haskell was barely mentioned. It seems they viewed the risk as "changing the projects language" rather than "using a non industry standard language".
I had a similar thought. Postgres is a great choice, but then they also went with Haskell ... I look forward to another blog post in 2-3 years detailed all the ways that Haskell failed them and that at the day they should have just gone with an industry standard language.