Minecraft wiki entry for Development_versions, associated text: Sea Turtles now play a sound when they lay eggs
Dolphins will now dry out at the same rate as they do in Java Edition; 120 seconds
Undamaged Mending items will no longer prevent damaged Mending items from being repaired (MCPE-80156)
Basalt can no longer be destroyed by Ghast fireballs (MCPE-75252)
Basalt blocks now take slightly more time to destroy
TNT no longer activates when a Redstone Torch is placed directly on it (MCPE-81258)
Experience Orbs now float in water (MCPE-64039)
Adjusted Netherite movement in lava (MCPE-65372)
Trade discounts from Hero of the Village and Curing Zombie Villagers now match the Java Edition (MCPE-70782)
Pistons can no longer be extended above the build height limit or into the void (MCPE-37825, MCPE-51067)