Funny you should ask. I actually started giving an honest go at learning Haskell before I started learning Erlang and later Elixir. So for me, I wouldn't say they were as eye opening as Haskell (truthfully Common Lisp and Scheme gave me more "woah!" moments than anything else so far) simply because of the order in which I learned them.

However, if you've never learned Haskell, OCaml, or F# I don't think it's a stretch to say that Elixir/Erlang's similar use of pattern matching and guards would have an eye opening effect that makes it worth learning. In both Haskell and Elixir/Erlang they're a core part of using the languages idiomatically. Once you see it in action you'd be hard pressed to not take some of the lessons with you elsewhere.

So, yes. Elixir and Erlang will make you rethink some assumptions about how to solve problems you probably never knew you had. Such as the "necessity" of explicit conditional statements. If anything you'll get better at using recursion to solve actual problems instead of just for contrived classroom-type problems.