Basically it’s just battling and trading with friends
When the duo of “Let’s Go” Pikachu/Eevee Switch games were announced, we heard some concerning news about the way online play worked. Statements were made that intimated that there wouldn’t be any real online functionality at all, and after a few full days of waiting, Pokemon Company designer Junichi Masuda has since clarified how Let’s Go will function online.
Okay, so first off many of the advanced features introduced in later games are out — Battle Spot, Wonder Trade, GTS, that’s all gone. Instead, after utilizing your Switch online subscription, you’ll be able to “battle and trade with friends.” That’s it, on top of local play.
While the jury is still out on Let’s Goas a whole, it’s clear that as a spinoff of sorts, it’s not going to be as comprehensive as a mainline entry. Temper your expectations folks! There’s still another “big” Pokemon game on the way for 2019.
The Pokemon Company Clarifies Let’s Go Games’ Online Functionality [Game Informer]