Minecraft wiki entry for Development_versions, associated text: MC-188669 – Clouds render in front of everything on "Fabulous!" graphics setting.
MC-188673 – Particles render in front of semi-transparent in "Fabulous!" graphics setting.
MC-188675 – Bed heads, bottom doors, and tall flowers drop two items.
MC-188678 – Milking a cow/mooshroom for milk or mushroom stew consumes the item without giving anything back.
MC-188691 – The player can no longer light a nether portal using a fire charge on the side of obsidian.
MC-188692 – Experience orbs render through end crystals in "Fabulous!" graphics setting.
MC-188694 – Some blocks' hitboxes are rendered through other blocks in "Fabulous!" graphics setting.
MC-188808 – Ice blocks on item frames are visible through chest blocks in "Fabulous!" graphics setting.
MC-188923 – Rain can be seen indoors while using "Fabulous" graphics setting.