Correct. The newest version of CouchBase mobile no longer supports CouchDB as a replication target. It can still be accomplish with the CouchBase Sync Gateway, but get complicated quickly.
I evaluated Couchbase mobile about a year ago and found although it worked well once setup there was a lot of overhead and the docs seemed a little all over the place and the fact that you can't also use the same DB on the web anymore with PouchDB meant I ultimately dropped it. It's a shame because there isn't really anything open source / self hosted like it for mobile.
