Theres no mutated ganon theme
Not sure what theme you're talking about, it's either track 57 or 60. Or you might thinking of a reused track from Breath of the Wild, which I didn't include.
Reused tracks from Breath of the Wild:
1.15 The King of Hyrule's Wish
2.07 Link's Memories: "Mipha's Touch"
2.23 Link's Memories: "Revali's Flap"
3.08 Link's Memories: "Daruk's Mettle"
3.22 The Arrogant Master Kohga (outro)
3.23 Master Kohga Battle
3.24 Link's Memories: "Urbosa's Hand"
4.02 Lost Woods
4.04 Encounter with the Deku Tree
4.08 Hestu Dance! (looped very quietly during the first cutscene with Hestu)
4.27 Zelda's Wish
5.13 Get Fanfare (Item)
5.15 Get Fanfare (Key Item)
5.26 A Korok Appears
5.32 Puzzle Solved Jingle
Robbie Guitar Riff
These BotW tracks can be found in the sound files for Age of Calamity, but they are not actually used:
1.19 Sheikah Tower: Activated
2.04 Sidon's Theme
3.21 Yiga Clan Hideout
4.07 Master Sword ~ The Deku Tree's Words
4.09 Akkala Ancient Tech Lab
4.12 Omen of the Blood Moon
4.20 Link's Memories: "Father and Daughter"
4.23 Link's Memories: "Return of Calamity Ganon"
4.31 Hyrule Castle
5.14 Get Fanfare (Spirit Orb / Rare Item)
5.23 Cooking Success
5.24 Major Cooking Success
5.46 Larger Than Life: Daruk
5.51 The Final Trial
5.54 The Divine Princess and the Five Champions
5.55 The Champions' Ballad Ending