I don't think we have anything to worry about. Season 3 ended less than a year ago. No one has said anything isn't happening. They're in negotiations/eeearly production...I would probably expect that to be what stage they were in even if no "news" got out. I'd put money on no new Rick and Morty until mid 2019, at the earliest.
Dan talking about all of this on his podcast makes the whole situation look like it might be the nothing that it is. Just a popular show moving at...about the pace we could expect. In due time!
Hooray for "news!"