Minecraft wiki entry for Development_versions, associated text: MC-236701 – New mountain biomes don't count towards "Adventuring Time" advancement.
MC-236938 – /jfr stop output does not have a link.
MC-237986 – Mobs specific to structures aren't spawning in their structures.
MC-238062 – Foxes and wolves don't spawn in groves.
MC-238761 – Adventuring Time does not account for the new cave biomes.
MC-238900 – Values of Infinity in noise settings in default worldgen.
MC-238912 – Powder snow strips can't generate exposed to the surface.
MC-238962 – Icebergs go all the way to ocean floor.
MC-239280 – Withers do not move down to follow the player when the wither's health is half or lower.
MC-239344 – All torches in mineshafts are facing the wrong way.
MC-239359 – Wither skeletons can only spawn on nether bricks.
MC-239689 – The "amplified" boolean in noise settings does nothing.