It's the Otherworld update! Check the description for details on what got replaced. (Look for Music IDs 62 until 88)

Removed Battlefield - The Throne of Heaven and Earth (EO1) for Martian Madness and replaced it with Battlefield - Flashing Blades (EO5).

Removed Labyrinth - The Deeps Ends of Ginnungagap from EOU2.

Shifted Labyrinth V - Porcelain Forest (EO3) from the Hallow to the Aether. Labyrinth V - Heavenly Keep (EO2) has taken its spot as the replacement for the Hallow.
Replaced Labyrinth - Ginnungagap (EOU2) with Labyrinth I - Ancient Forest (EO2) for Daytime Jungle.
Replaced Labyrinth VI - Forbidden Woods (EO2) with Labyrinth VI - Empyreal Bridge (EO5) for Nighttime Space.
Replaced Labyrinth I - Ancient Forest (EO2) with Labyrinth - Ginnungagap (EOU2) for the Glowing Mushroom Field.
Replaced Labyrinth V - Heavenly Keep (EO2) with Labyrinth V - Untamed Garden (EO5) for Daytime Space.
Replaced Labyrinth - The Deep Ends of Ginnungagap (EOU2) with Labyrinth VI - Forbidden Woods (EO2) for Underground Jungle.