Certain headers for classes that are to be removed (e.g. plugin api) were not updated to prevent merge conflicts.
Merely just a protocol change, nothing new has been implemented (such as bees) and won't be until bedrock 1.14 is released.
This should make the process of translating entity metadata a whole lot easier and more organized. Future features involving entities and checking if they're capable of doing certain things should also be much easier now.