I recently went through something similar when I submitted julia-repl to MELPA. I am in two minds about this: I did get a lot of helpful suggestions which made the code more compatible across Emacs versions, but at the same time it was clear that the people helping me were very busy otherwise, which resulted in delays (my fault too, of course).
Instead of making it mandatory, it could be started as a voluntary scheme: people could ask for code reviews, and get help from experts. OTOH, I imagine that all the developers qualified to do this are very, very busy, and perhaps think that their time would be better spent improving Julia or the packages they contribute to.
In any case, I find reading Julia code of various packages very helpful. I learned a lot this way about optimization, code organization, and mundane details like setting up the documentation.