Well, sorta; the Array -> WrappedArray conversion relates them. The intent is to let you use Seq methods on Arrays, and that part works. But you don't also get RichSeq methods, even though you can use them on Seqs. I'm sure that seems obvious to you, but do you see how the author's intent is misaligned with the result?

I think that's the key takeaway: implicits aren't really a way of extending a library type, they just have some of the same effects. You still have to care about the distinction between the original type and the enhanced one, and that's, well, complex.