It is especially strange since even limited series that ended definitively, like The Queen’s Gambit, had people pushing for a continuation. Meanwhile, Shogun was also supposed to be a limited series, but in that case, its popularity actually did lead to it being renewed for two more seasons. Shogun already covered all of its book material as well, so now the showrunners have no other option than to create totally original plot elements.
So it is not like Brand New Cherry Flavor would have been unprecedented if Netflix had given it a second season.