The secret techniques showcased in the trailer are Chop Down (which seems to be a replacement for Cut), Sea Skim (Surf) and Sky Dash (Fly). No sign of replacements for Strength and Flash, but presumably those will exist.
The special moves Pikachu and Eevee are seen using are exclusive to your partner. Pikachu has the special partner move Pika Papow, which receives a boost in strength depending on your bond with Pikachu. It can also use the move Splishy Splash, which is a Water type move with the chance to paralyze the opponent.
Where Eevee is concerned it has a wide variety of exclusive moves: Veevee Volley, Bouncy Bubble, Buzzy Buzz and Sizzly Slide. Like with Pika Papow, the power of Veevee Volley grows depending on your bond with Eevee. Bouncy Bubble is a Water type move which will heal Eevee for half of the damage dealt to the opponent. Buzzy Buzz is an Electric type move that can paralyze the opponent. Finally, Sizzly Slide is a Fire type move that always leaves the target with a burn status condition.
Finally, the trailer confirmed that Gym Leader Erika is still in-charge of the Celadon City Gym and gave us a showcase of the city, which is looking great in the new game.
Alongside the trailer it was also confirmed that a special Pokémon Let's Go Eevee/Pikachu Nintendo Switch bundle will be released! The bundle includes a special Pokémon themed Switch as well as a digital copy of either Pokémon Let's Go Eevee or Pokémon Let's Go Pikachu and a Pokéball Plus.
The set is being released worldwide and the Joy-Cons and dock will only be sold separately in Japan through Pokémon Center Online stores and My Nintendo stores. Will you be picking one up?