Who exactly claims Erlang is dead? The referenced article is SEO-infected garbage that also claims Haskell and Perl are dead.
However, as people from other domains started employing its principles, Erlang's value diminished. E. g., if we now write supervisors in Python that run servers, event handlers and FSMs written in C++, and the system works fine, we don't really need Erlang.
I'd just ignore it as low quality click bait if I were you.