After completing the Main Story, you can rematch the Champion Cup as many times as you would like. This time around, you can select which opponents will be added to the tournament or if you would prefer a random set of foes. There are twenty-six trainers you can face this time around, including Hop, Leon, Marnie, the eight Gym Leaders, and fifteen Random Pokemon Trainers. Unlike the Random Pokemon Trainers, the Gym Leaders and other Main Characters have stronger Pokemon and each have the ability to Dynamax/Gigantamax one of their Pokemon.
Milo, of course, is one of the eight Gym Leaders you can face when rematching the Champion Cup. Milo still focuses on using Grass Type Pokemon, having Shiftry/Ludicolo, Eldegross, Bellossom, Cherrim, and Flapple/Appletun when in battle. All of Milo's Pokemon will be between Levels 60-62, and he'll always Gigantamax his Flapple/Appletun. Because of this, Milo is still weak against Flying Type Pokemon & Attacks. Milo continues to also struggle against Fire Type Pokemon & Attacks, since most Grass Types are extremely weak against them as well.
After defeating both the Isle of Armor and Crown Tundra DLC Packages, Milo's Champion Cup Rematch Pokemon Team will have changed slightly. All of his Pokemon will now be at higher levels, and he'll have replaced his Bellossom with Tsareena.