All moves that can't be accessed from Metronome as of Gen 7 are...
After You, Assist, Bestow, Chatter, Copycat, Counter, Covet, Destiny Bond, Detect, Endure, Feint, Focus Punch, Follow Me, Freeze Shock, Helping Hand, Ice Burn, Me First, Mimic, Mirror Coat, Mirror Move, Nature Power, Protect, Plasma Fists, Quash, Quick Guard, Rage Powder, Relic Song, Secret Sword, Sketch, Sleep Talk, Snarl, Snatch, Snore, Struggle, Switcheroo, Techno Blast, Thief, Transform, Trick, V-Create, and Wide Guard. Also, Metronome can't be selected by itself neither Z-Moves. Though Z-Metronome uses the actual Z-Move.
NOTE: Bulbapedia's list was incomplete, so I added a few moves that I remembered couldn't get selected by Metronome.