The replacements are made to be more in-line with the design queues from the 2019 Texture Update, as well as the styles present in Dark Mode.
Redesigned the Chest, Large Chest, Ender Chest, Shulker Box, Barrel, Furnace, Blast Furnace, Smoker, Horse (and other variants), Llama, and Mob Effect screens on Bedrock Edition to be more in-line with their layouts and appearances on Java Edition! More screens will be reworked and adjusted in future releases.