I think it is too early to say which projects will be next, but some ideas include: choosing lead images, editing wikidata descriptions, and refining categorization of topics.

Joaquin, I agree that lessons learned would be helpful.  As someone who came to the project at the very end, I don't feel entitled to point out things that should have been done differently.  As a member of the team that made the decision to pause development, however, I would be happy to help establish criteria that projects need to meet (as a minimum) in order to see continued effort.  Given my limited bandwidth, this is not something I can promise anytime soon and I encourage others to take a first stab.

-J