Although they are the first main-series Pokemon role-playing games for the Nintendo Switch, Let's Go, Pikachu! and Let's Go, Eevee! are a separate project from the Pokemon game on the same platform that was teased during Nintendo's E3 2017 Nintendo Direct on 13 June 2017 presentation which is scheduled to be released in ''late 2019''.

Can we conclude that is pokemon let's go a main series game?
yes