At the moment in my newish SS save, I picked it up going against Pryce, just to be on the safe side. It turned out that I didn't need it; my Heracross and newly evolved Ampharos with Iron Tail took care of the old man. Otherwise the red Gyarados will either stay in PC, or I might actually make a new team once the Kanto part starts. That is, ditch my exclusive Johtoan Pokémon and start a new team with only Kanto Pokémon in it. Would take a lot of time to train a completely new team, but at least I wouldn't be grinding as easily as usually. That is, for the first time in a long time I'm even paying a relatively close attention to Natures and smart movesets, and the game has gotten even easier than it normally is. With new Kanto guys on the party, I'd be underleveled, and I'm fine with that.
Thinking of my complete Kanto team being something along the lines of the red Gyarados, Persian, Ninetales, Dragonite, Hitmonlee and Hypno. Would feature many Pokémon I've never really used before, and be, like, my second ever team without a STAB EQ!
The first one is going on right now as soon as Pupitar will evolve into Tyranitar...