Previous PU mons that were removed consist of: Dodrio, Gigalith, Pelipper.  Drought and Drizzle have also been banned. You can still use sun and rain with manual setters.
sumo
Comfey
Crabonminable
Dugtrio-Alola
Gumshoos
Komala
Lurantis
Mudsdale
Oranguru
Oricorio
Oricoro-Pa'u
Oricorio-Pom-Pom
Oricorio-Sensu
Palossand
Pyukumuku
Raichu-Alola
Raticate-Alola
Sandslash-Alola
Shiinotic
Silvally (all forms)
Togedemaru
Toucannon
Tsareena
Previously NU mons
Aggron, Claydol, Cradily, Ferroseed, Kecleon, Miltank, Sandslash, Zangoose
Previous PU mons
Altaria, Ampharos, Arbok, Ariados, Armaldo, Articuno, Audino, Avalugg, Banette, Basculin, Bastiodon, Beartic, Beautifly, Beedrill, Beheeyem, Bellossom, Bibarel, Bouffalant, Butterfree, Cacturne, Camerupt, Carbink, Carnivine, Castform, Chatot, Cherrim, Chimecho, Clefairy, Combusken, Corsola, Crustle, Cryogonal, Dedenne, Delcatty, Delibird, Dewgong, Ditto, Drifblim, Dunsparce, Dusknoir, Dustox, Electrode, Emolga, Farfetch'd, Fearow, Flareon, Floatzel, Furfrou, Furret, Gabite, Girafarig, Glaceon, Glalie, Gogoat, Golduck, Golem, Gorebyss, Gothitelle, Gourgeist, Grumpig, Heatmor, Huntail, Hypno, Illumise, Jumpluff, Kadabra, Kingler, Kricketune, Lapras, Leafeon, Leavanny, Ledian, Lickilicky, Lopunny, Lumineon, Lunatone, Luvdisc, Luxray, Magcargo, Maractus, Marowak, Masquerain, Mawile, Meganium, Meowstic, Metang, Mightyena, Minun, Misdreavus, Monferno, Mothim, Mr. Mime, Muk, Ninetales (no drought), Ninjask, Noctowl, Octillery, Pachirisu, Parasect, Pawniard, Persian, Phione, Pidgeot, Plusle, Politoed (no drizzle), Prinplup, Probopass, Purugly, Quagsire, Raichu, Rampardos, Rapidash, Raticate, Regice, Regigigas, Relicanth, Roselia, Rotom-Fan, Rotom-Frost, Sawsbuck, Seaking, Seviper, Shedinja, Simipour, Simisage, Simisear, Slaking, Smeargle, Solrock, Spinda, Stantler, Stoutland, Stunfisk, Sudowoodo, Sunflora, Swalot, Swanna, Swoobat, Tangela, Torkoal (no drought), Trevenant, Tropius, Unfezant, Unown, Ursaring, Vanilluxe, Vespiquen, Volbeat, Vullaby, Wailord, Walrein, Watchog, Whiscash, Wigglytuff, Wobbuffet, Wormadam, Zebstrika