Just want to say – don’t wait for new content, this snapshot is aimed at technical improvement of MC, therefore this update doesn’t contain new things. Either way, 17W43A is Minecraft optimization that reduces lags making the gameplay more enjoyable.
New data packs. Now you can change the names of items, crafting recipes, achievements and other values that play an important role in Minecraft.
The game now uses LWGJL. This is very important for Mac OS and Linux owners, you will improve stability if you install this snapshot.
These are not all changes, some are not yet available or are being developed. The release of Minecraft 1.13 will take place after the end of beta testing.