I don't know if the development team is aware of these already, but I saw that there wasn't a thread on these yet, so I wanted to make one just in case. So it appears that the firework boost effect isn't working with the Elytra like it should be. The rocket goes off, but you don't get the boost effect. Also, it appears that Wither Skelton spawns are broken in the Nether. I explored three different Nether fortresses and didn't see a single skeleton. Plenty of pigmen and blazes, but no skeletons. Other people have confirmed that it wasn't just me. This is problematic when you're trying to get a beacon. Unless this is an intentional choice to prevent people from spawning the Wither and using its explosive effects to grief the map, I'm not sure.