According to Reddit user LiarInGlass, who has an early copy of the game, motion controls are not required to catch Pokemon in Handheld Mode. All you have to do is to press the A button at the right time to catch it.
If that is the case, there is no reason not to support the Nintendo Switch Pro Controller in Pokemon Let’s GO Pikachu/Eevee. Hopefully they’ll patch that in soon.
What do you think?