I think the title is misleading. This isn't really about either language in production environments. As other commenters mentioned, a post about production would cover topics like whether there were any tooling / dependency updates that broke a build, whether they encountered any noticeable bugs in production caused by libraries / run time, and how efficiently the run times handle high load (e.g., with GC).

This is more about syntax differences. Even then, I'd be curious how well both languages accommodate themselves to teams and long term projects. In both cases, you will have multiple people working on parts of the code base. Are people able to read and modify code they haven't written -- for example, when fixing bugs? When incorporating new sub components, how well did the type systems prevent errors due to refactoring? It would be interesting to know if Haskell prevents a number of practical problems that occurred with OCaml or if, in practice, there was no difference for the types of bugs they encountered.

This blog post feels more like someone is comparing basic language features found in reviews for new users rather than sharing deep experience and gotchas that only come from long-term use.