Does beta not let you translate articles yet for the Dutch immersion?
It does let you, I myself already added a few articles and I saw that other people added a lot more too. Though the discussion button seems to be disappearing for some people.
Maybe the Duolingo staff is fixing or adding something, mine for the moment is there.
Where are the articles you uploaded? I can't see any articles in the immersion section at all nor can I upload any documents myself.