If timed right, the ender dragon can be killed before destroying the end crystals by placing and exploding beds under the dragon's head.  For example, https://www.youtube.com/watch?v=Bf1qdEN32DI, and a more detailed description of how to reproduce this is available here.

Given that doing so with explosions has been extremely difficult in the past, I presume that this is unintended behavior (albeit with minimal impact outside of speedrunning).

[IMO: Personally, I think this should be kept in singleplayer, but is worth reporting as unintended nonetheless.]