Mojang have shared a change on the plan for the forthcoming Minecraft: Java Edition 1.13 update and the Update Aquatic (Minecraft 1.14).
We’re going to hold back the official launch of 1.13 and merge that release with all the features we’d planned for the Update Aquatic. [...] we were planning on releasing the rather technical 1.13 update, which includes equally exciting-sounding things like a new world format, a new command parser, data packs and the elusive rewrite of world generation. [...] However, because our world generation overhaul is taking a little longer to get ready, we’re going to hold back the big 1.13 release and put it out at the same time as the Update Aquatic. In fact, the Update Aquatic will become 1.13!
There's not all bad news though, as a consequence of this change you will be playing the Update Aquatic sooner than previously planned:
As a result, however, this means we can actually start snapshotting Update Aquatic features much earlier than previously planned! Lucky you! So, get ready to take a dip… soon… ish!
You can expect the first Update Aquatic snapshot in the coming weeks, Dinnerbone tweets...
There will not be a snapshot today. As I said in last weeks snapshot blog post, we're moving offices and aren't in a very good position to do snapshots for a little while. *maybe* next week, but not guaranteed.— Nathan Adams (@Dinnerbone) January 24, 2018