ok so here's what I've gathered
GameMill released one or two games yearly for a long time, until Nickelodeon Kart Racers 1. Presumably due to the commercial success of that game, they became able to start making more and more games in a given year. Kart Racers 1 released in 2018 and as far as I can tell was the only game they released in 2018?
Anyways, 2019 gave us 2 games, American Ninja Warrior and Street Outlaws, 2020 gave us 3 games, GI Joe, Cobra Kai and Kart Racers 2, 2021 gave us 4 games, Street Outlaws 2, Cruis'n Blast, Nerf Legends and NASB obviously, then 2022 gave us 4 games as well, Little League World Series 2, NHRA Championship Drag Racing, Cobra Kai 2 and Kart Racers 3.
Finally, in this year, 2023, we have Nascar Arcade Rush and Avatar Quest for Balance confirmed to be releasing this year and a new leak that seems to imply Skull Island Rise of Kong will also be releasing this year. That puts us at 3 confirmed GameMill games this year, but ever since 2021 they've managed to put out 4 games per year.
In conclusion, mayyyybe it's a little too early to call anything just yet