I'm still confused... (and maybe more and more confused)

The lang com and the policy (assuming you talk about this language proposal policy[1]) is about creating new project, right?

Here we are talking about adding content to an existing project (and more precisely to ease and improve the adding of content, since even without a specific lang code the content can still be add).

Isn't this two different things?

Cdlt, ~nicolas

[1] https://meta.wikimedia.org/wiki/Language_proposal_policy