You're changing the specs on an approved kata. Don't do that.

Normally, I'd complain about changing the example solution, but here the author's example solution no longer passed tests, so it had to be changed. But it's a clear indication there's something wrong if you have to change it. Because you shouldn't - that's then not the author's code anymore, and his name will still be on it.

Given a two-dimensional array of integers, return the flattened version of the array with all the integers in the sorted (ascending) order.

Hence, no.

After seeing the solution I feel like a moron xD Didn't see the wood for the trees

Haskell tests should be written in a way so the compiler still knows the types for the test cases without clearly inferable type so function can be written more general for any Ord a, instead of having to be type specific.