Specifically says that Ash decided on using Sirfetch’d, Dragonite, and Lucario to fight if he overcomes Steven.
Gigantamax Gengar is Ash’s trump card against Steven
Cynthia is referred to be the “strongest Dragon-type user”
Even though Alain isn’t a regional Champion, he’s counted as a League Champion
Ash’s strategies against Steven are a lot more tactical than usual
Steven prides on how strong defensively his Pokémon are which will be Ash’s main struggle
Magazine makes a point that people pay a lot of attention to Diantha and Leon’s battle
”Finally, the world will see the true hidden power of the Alola Champion”

They are really pushing the point that Ash is fighting for all his Pokémon instead of just his main team this time. He’s applying experience from his other Pokémon into this battle, so we may or may not see some old strategies being used here, or cameos of Ash’s old Pokémon.
Also says Ash powered up Dragon Rush and Will-o-Wisp which will be used to counter Steven’s astronomically strong defenses. They hype Steven up as the “Iron Wall” of the Masters 8, no one has been capable of beating his defenses.
Leon prefers to mix overwhelming his opponents and entertaining the crowd, along with being an expert of Gigantamax
Alain prefers to dive straight in with explosive attacks
Diantha prefers to create defensive shields and use a variety of different moves that induce status conditions
Lance prefers to use decisive attacks that finish off his opponents with one blow
Iris brings out the full potential of her Dragon-type Pokémon but also can make use of Pokémon with double types
Steven has the ultimate defense and is easily capable of draining his opponent’s stamina
Cynthia is the strongest all rounder, she prefers to let her opponent’s move first and can adapt to any situation
Ash is a tactical genius and fights with the experience of all his Pokémon. He is also a master of Mega Evolution, Gigantamax, and Z-Moves.