I just checked out the trailer. Seems cute and fun enough. I hope there won't be too many people walking into Amphibia expecting it to be as lore-heavy as Gravity Falls, because it looks to me like the show will focus more on silly adventures in a humble little frog village.
As long as it doesn't make the same mistakes as BCG by instead making its "self-centered" protagonist actually likable and using a bigger cast of recurring characters, then yeah. Amphibia will kill Big City Greens.