Dropping my level_up_learnsets.h over here in case anyone wants to use it. It's basically yours Buffel, but tweaked to the latest commits of Egg's branches (battle_engine_v2 and pokemon_expansion), so it's ready to be used in a merged branch.
-Fixed learnset pointers (for example, the Alolan Forms being written as Pokémon_1 instead of AlolanPokémon or the Janmo-O line having their 2nd "o" in lowercase letters)
-Fixed various move labels (MOVE_HIGH_JUMP_KICK, MOVE_FEINT_ATTACK, MOVE_SMELLING_SALTS, MOVE_NATURE'S_MADNESS, MOVE_KING'S_SHIELD and maybe a few more)
-Commented out the evolution moves and the moves that were not defined in the battle_engine_v2 yet.
-Added the learnsets from SwSh to Meltan and Melmetal.
EDIT (23/02/2020): I updated the file just now, adding the learnsets for Lycanroc's Dusk and Midnight Forms since they were implemented in Egg's branches recently.
I skipped a few repeated moves like Midnight Form learning Sand Attack at Lv4 or Bite at Lv7 because it already learned those moves at Lv1 and realistically, that wouldn't happen in normal gameplay in a standard Pokémon game. The only reason to leave one or the other is Move Reminder shenanigans.
Whoever decides to use this file can change that sort of stuff as they see fit though, naturally.
EDIT (21/04/2020): I updated the file just now, uncommenting the moves Plasma Fists, Photon Geyser and Double Iron Bash since they were added to the battle_engine_v2.
I also changed the labels for MOVE_KING_S_SHIELD, MOVE_FOREST_S_CURSE and MOVE_LAND_S_WRATH, since I fixed them a few days ago.