When it aired on Toonami back in the day the show never had the Hot Wheels suffix; it was simply called “Acceleracers”.
My guess was that the movies were so seperated from the brand of toys it was based on that it was able to stand on its own. Shame it got cancelled just as the plot got kicked off. Mattel cancelled it because of a change in staff and opted not to continue Acceleracers which had been slated for a second season according to the shows toy designers. Shame.
Though we might be getting a sequel to it in a weird way…