Well since we technically now have an idea what the Alolan Regional Dex for other region-based Pokemon, going to give my two cents on the matter. As you said, we don't know what's going to be viable, however I'm going to list down what I personally think will likely be "strong" or part of any good stuff team for the upcoming VGC 17 format. Obviously neglecting legends, UBs, Ash Greninja, Magearna, and maybe some Kanto-based Pokemon due to the mechanics of regional variants. Also placed somewhat of a footnote for these Pokemon to briefly explain why they might be used more often than others. So here's what players will immediately look into without having an extensive into their moves or BSTs.
Kanto
Clefable - Bulky Fairy-type with Redirection
Arcanine - Intimidate / Defensive Wisper / Offensive Fire-type Pokemon
Alakazam - Fast Psychic-type
Machamp - Bulky Fighting-type with Wide Guard
Slowbro - Slow TR setter
Alolan Muk - Decent Typing
Gengar - Fast Special Attacker / Variable Support Options (Wisp / Trick Room / Taunt)
Chansey - Minimize Spammer
Kangaskhan - Fake Out user with decent bulk and power.
Starmie - Fast Water-type with diverse coverage
Tauros - Fast Intimdate user/ Offensive Attacker.
Gyarados - Intimidate user / Setup Mon / Decent Defensive Wall
Lapras - Counters most Water-types
Ditto - Well ...its Ditto so Imposter shenanigans
Jolteon - Breaks 130 Speed / Fast Electric Attacker
Aerodactyl - Checks most Flying-types / Wide Guard
Snorlax - Bulky Offensive Pokemon
Dragonite - Setup / Variety Attacker / Potential Defensive Viability / BST of 600
Johto
Crobat - Breaks 130 Speed / Fast Support
Politoed - Drizzle Setter
Slowking - Oblivious Trick Room
Granbull - Bulky Fairy-type with Intimidate
Scizor - Bulky Steel-type with Priority Bullet Punch, Feint, and other support
Porygon2 - Defensive Wall / Trick Room setter / Bulky Offensive attacker
Smeargle - Dark Void and Learns Every Move in the Game.
Hoenn
Hariyama - Bulky Fighting-type with Wide Guard / Fake Out
Sableye - Prankster user ( Wisp / Swagger / Quash )
Flygon - Dragon-type with Immunity to EQ via Levitate. Also has Feint
Milotic - Intimidate Deter with Competitive ability / Bulky Water-type
Salamence - Premier Dragon Pokemon with Intimidate / High Offensive Coverage
Metagross - Premier Bulky Steel-type with High Defensive / Offensive Qualities.
Sinnoh
Gastrodon - Storm Drain User / Bulky Water-type
Garchomp - "Go-To" part Ground-type for STAB Earthquake / Decent Resistances with Dragon-type / Troll 102 Base Speed
Lucario - Glass Cannon but with Capable Offense with STAB CC. Has Follow Me
Weavile - IMO the Anti Meta Pokemon (for a time) / Base 125 Speed / Fake Out + Ice Shard priority
Electivire - Immunity to Electric moves / Diverse Coverage
Porygon Z - Strongest Special Normal-type from the Non-Alolan Pokemon
Unova
Whimsicott - Fast Fairy-type / Prankster user with Support Options ( Tailwind, Encore, Fake Tears, Taunt )
Krookodile - Dark-type with Coverage options + STAB EQ / Intimidate
Braviary - Tailwind support / Defiant
Mandibuzz - Support Coverage with Tailwind, Snarl, Foul Play, Whirlwind
Kalos
Talonflame - Priority Gale Wings / Tailwind / Decent Support (Taunt / Wisp)
Sylveon - Bulky Fairy-type with Helping Hand Support / Note: Might not have Hyper Voice
Goodra - High Special Defense to deal with Weather Teams (Rain / Sun), Diverse Coverage
Klefki - Prankster user with Various Options (T-Wave, Screens, Swagger, Foul Play)
Trevenant - Decent TR user against most Water and Psychic-types.
Well that's a personal list of "strong" Pokemon people should prepare for, or consider using for the upcoming format without going too deep into each mon's viability. Looking forward in in seeing your individual analysis @MagnusHexem. If you need any help, can always pm me or any of the competitive moderators as this might prove to be a notable task.
