Darkrai had Embargo through Level Up in Diamond and Pearl but lost it from Platinum onwards. Could still learn through TM.
Dialga, Palkia and Giratina all had Heal Block through Level Up in Diamond and Pearl but lost it from Platinum onwards.
Corsola had Safeguard as an Egg Move in Gen 2 but never again. Can still learn through TM.
Shaymin had Lucky Chant as a Level Up move in Diamond and Pearl but lost it from Platinum onwards.
Kabuto had Aerial Ace through TM in Gen 3 but never again.
Vileplume had Sleep Powder through Level Up in Gen 1 but never again.
Vileplume and Victreebel had Poison Powder through Level Up in Gen 1 but never again.
Steelix had Rock Polish through Level Up in Gen 4 but never again. Can still learn through TM.
Vullaby and Mandibuzz had Iron Defence through BW2 Move Tutor, but no longer in ORAS.
Poliwag and Poliwhirl had Amneisa through Level Up in Gen 1 but never again.
Clefable had Minimize as a starting move in Gen 1, lost it in Gen 2, and regained it from Gen 3 onwards.
Lucario had Dark Pulse as a starting move in Gen 4 and 5 but lost it in Gen 6. Can still learn through TM.
Ekans had Crunch as an Egg Move in Crystal but never again.
Mightyena had Crunch as a Level Up move in gen 3, lost it in Gen 4 onwards and regained it in ORAS.
Vibrava and Flygon had Crunch as a Level Up move in Gen 3, but never again.
Porygon-Z had Wonder Room as a Move Tutor move in BW2 but lost it in ORAS.
That does it for all Gen 1-4 TM moves plus some extras. I'll cover the Gen 5 and 6 TMs/HMs in the next post because my laptop's being an asshole and forcing a restart
Dialga, Palkia and Giratina all had Heal Block through Level Up in Diamond and Pearl but lost it from Platinum onwards.
Corsola had Safeguard as an Egg Move in Gen 2 but never again. Can still learn through TM.
Shaymin had Lucky Chant as a Level Up move in Diamond and Pearl but lost it from Platinum onwards.
Kabuto had Aerial Ace through TM in Gen 3 but never again.
Vileplume had Sleep Powder through Level Up in Gen 1 but never again.
Vileplume and Victreebel had Poison Powder through Level Up in Gen 1 but never again.
Steelix had Rock Polish through Level Up in Gen 4 but never again. Can still learn through TM.
Vullaby and Mandibuzz had Iron Defence through BW2 Move Tutor, but no longer in ORAS.
Poliwag and Poliwhirl had Amneisa through Level Up in Gen 1 but never again.
Clefable had Minimize as a starting move in Gen 1, lost it in Gen 2, and regained it from Gen 3 onwards.
Lucario had Dark Pulse as a starting move in Gen 4 and 5 but lost it in Gen 6. Can still learn through TM.
Ekans had Crunch as an Egg Move in Crystal but never again.
Mightyena had Crunch as a Level Up move in gen 3, lost it in Gen 4 onwards and regained it in ORAS.
Vibrava and Flygon had Crunch as a Level Up move in Gen 3, but never again.
Porygon-Z had Wonder Room as a Move Tutor move in BW2 but lost it in ORAS.
That does it for all Gen 1-4 TM moves plus some extras. I'll cover the Gen 5 and 6 TMs/HMs in the next post because my laptop's being an asshole and forcing a restart