Pokémon Sword and Shield cut a lot of content from the series, which extended to the special moves used by Pokémon in battle. The number of Pokémon in the series had grown so large by Gen VIII that The Pokémon Company decided to cut the roster in Pokémon Sword and Shield, leading to the so-called Dexit controversy.
The size of the Pokémon series meant that the developers decided to reduce the scope for Gen VIII. This meant a smaller number of available Pokémon in the Galar region, along with the removal of Mega Evolutions and Z-Moves. It wasn't unheard of for the Pokémon series to remove elements between generations, but it had never been to this degree before. This led to a vocal backlash against Pokémon Sword and Shield from the fans, who seemingly took over the discourse surrounding the games. Ultimately, the Dexit situation didn't affect sales, as Pokémon Sword and Shield became the third best-selling entries in the history of the series, behind only Pokémon Gold and Silver and Pokémon Red and Blue. A number of Pokémon returned to the series alongside The Isle of Armor and The Crown Tundra DLC expansions, but there are still plenty of Pokémon that are currently in limbo.
It wasn't just Pokémon that were cut in the jump to Gen VIII, however. The Pokémon Company took the chance to cut moves from the game as well. If a Pokémon is traded into Pokémon Sword and Shield, then they will retain the move, but it cannot be used in battle. These moves have a generic description, saying that they cannot be used and should be forgotten. Once the move has been deleted, it cannot be restored. All Z-Moves were cut from Pokémon Sword and Shield, but there were also regular moves that were taken out of the series, too. A big victim of these cuts is the special partner moves from the Pokémon: Let's Go games, even though they were also on the Nintendo Switch. These were exclusive to the Eevee and Pikachu from those games and they existed to make the starter Pokémon viable throughout the whole game, so it's not surprising that they were cut from mainline entries in the series.
The Cut Moves From Pokémon Sword & Shield
According to Bulbapedia, the following is a list of all of the moves that no longer work in Pokémon Sword and Shield:
- Assist
- Baddy Bad
- Barrage
- Barrier
- Bestow
- Bide
- Bone Club
- Bouncy Bubble
- Bubble
- Buzzy Buzz
- Camouflage
- Captivate
- Chip Away
- Clamp
- Comet Punch
- Constrict
- Dizzy Punch
- Double Slap
- Dragon Rage
- Egg Bomb
- Embargo
- Feint Attack
- Flash
- Flame Burst
- Floaty Fall
- Foresight
- Freezy Frost
- Frustration
- Glitzy Glow
- Grass Whistle
- Heal Block
- Heal Order
- Heart Stamp
- Heart Swap
- Hidden Power
- Ice Ball
- Ion Deluge
- Jump Kick
- Karate Chop
- Lucky Chant
- Magnet Bomb
- Magnitude
- Me First
- Meditate
- Miracle Eye
- Mirror Move
- Mirror Shot
- Mud Bomb
- Mud Sport
- Natural Gift
- Needle Arm
- Nightmare
- Odor Sleuth
- Ominous Wind
- Pika Papow
- Psycho Boost
- Psywave, Pursuit
- Punishment Rage
- Razor Wind
- Refresh
- Return
- Rock Climb
- Rolling Kick
- Rototiller
- Sappy Seed
- Secret Power
- Sharpen
- Signal Beam
- Sizzly Slide
- Sky Drop
- Sky Uppercut
- Silver Wind
- Smelling Salts
- Snatch
- Sparkly Swirl
- Spider Web
- Spike Cannon
- Sonic Boom
- Splishy Splash
- Steamroller
- Synchronoise
- Tail Glow
- Telekinesis
- Trump Card
- Twineedle
- Wake-Up Slap
- Water Sport
- Wring Out
- Veevee Volley
- Zippy Zap.
Just because a move was cut in Pokémon Sword and Shield, it doesn't mean that it's gone forever. There were some moves cut from Pokémon Sword and Shield that returned in the Expansion Pass, as the Pokémon they were associated were added back to the series. This includes Kinesis, the signature move of Kadabra and Alakazam, when they returned in The Isle of Armor expansion. The revolving door nature of the series going forward means any move can return, but it also means classic moves could also be cut in future Pokémon video games.
Source: Bulbapedia