Yes, that is my point. In order to demonstrate experience you really need to show work on something that justified Erlang, not just that you understand the syntax of Elixir and the basics of working with the Erlang VM. And usually a "weekend project" does not qualify (though that really depends on the project).

But I do think most companies that are looking for Elixir experience would be happy with your weekend project if was actually used by people in a way where Elixir could shine.