Minecraft wiki entry for Development_versions, associated text: Improved underwater visibility in all sorts of water, water-filled caverns in particular.
Oxidized Copper Block variants can now be waxed
Tweaked which blocks can be placed on pointed dripstone, to match the Java Edition (MCPE-116098, MCPE-116056, MCPE-116050)
Pointed dripstone now correctly breaks when pushed by piston (MCPE-116095)
Dripstone and pointed dripstone now have correct sounds when walking/jumping on them (MCPE-119694)
Glow lichen is now under the nature category of the Creative inventory (MCPE-122600)
Lightning Rods now correctly activate Observers when struck by lightning
Big dripleaf can now be waterlogged
Big dripleaf now untilts correctly after getting hit by a projectile (MCPE-121666)
Small dripleaf can now also be placed on dirt, farmland, grass, moss block, and podzol as long as its stem is underwater
Moss block now blocks water (MCPE-121796)
Ladder, vines, twisting vines, weeping vines, sweet berry bush, nether sprouts, and fire can now be placed on Moss blocks (MCPE-121828)
Spore Blossom correctly drop itself when broken with Shears (MCPE-122054)
Mobs can now pathfind across moss blocks (MCPE-121967)
Lush caves can now contain classic "jungle" vines
Fixed a bug where the screen reader did not read the focused button on some screens
Fixed a bug where English screen reader pronounced "A button" as "a button", now saying "Button A" instead
Trident in Players' and Mobs' hands are now correctly positioned in all perspective modes (MCPE-116681)
Trident raising animation modified for first person to more closely match the previous version
Water Buckets can now be used to pick up fish (MCPE-94520)