In DC lore, Accelerated Man is the Earth-19 version of the Flash.
If this version of Accelerated Man is at all like his DC Comics counterpart, he’ll probably be one of the good guys in Central City.
If this version of the character is also the speedster of Earth-19, the big question is what brought him to Earth-1.
Grodd has only shown interest in bringing war to Earth-1 to get revenge on Team Flash for banishing him to Gorilla City, so Earth-19 likely isn’t in any especial danger.