Google Code Jam 2019 has been announced. You may read the schedule. To register, you'll have to wait until March 5.

Unfortunately, there will be no Distributed Code Jam in 2019. I think that this has something to do with DCJ platform not receiving any substantial updates for the last three years. Maybe people who made it have already left, and no one can keep it working. It will be sad if this year's Distributed Code Jam is going to be the last.