To be honest, it looks like the author started with that super-hostile bloom/weed thing but by the 2nd novel he retconned it out. After that they made a big thing about how "the discrimination is all in your imagination". Which considering it was only a couple of episodes later in the anime, it all felt especially jarring.
So, they're not really doing the whole bloom/weed thing after all now. Just an occasional nod, with un-named male blooms scoffing at the MC as he's given yet more positions of authority. And nobody's used the terms Bloom and Weed at all now since around episode 6.
It's like they spend the first 3 episodes nailing home this particular point about how the blooms all vocally detest the weeds, literally 10+ times per episode they make the same point. Then, from episode 4 onwards we're supposed to believe it never happened and any weed who feels discriminated against is delusional. And it's all capped of with this cheesy "we're all at highschool together, yay" speech by the Council President around the end of Volume 2, and since then the discrimination has basically vanished like it never existed.
I think the writer decided the real point was that he needed to group his MC with the "A crowd" who have all the power, and having this ongoing thing of ending discrimination against the "lower classes" was going to conflict with that. So, rather than focus on how the "peasants" are discriminated, it's now a story of the fallen prince, who really should be in the royal court, not slummin' it with the lowly plebs. Having an ongoing plot of raising the masses to freedom would seriously complicate things once MC's rightful place on top of the hierarchy is recognized.
Yeah, basically Weed/Bloom is out now. Taboo and never to be mentioned in-universe again. And book 3 is apparently about a 9 magical highschool sports tournament. Which begs the question why they have this entrance exam and a 2-tiered thing within every school. Does every school have this bloom/weed divide? It makes no sense to replicate the same "2 class" system within 9 identical schools, when you could just have e.g. 4 top-grade schools and 5 mid-grade schools without the disruption of a course/class divide, especially since it's been made clear that there's no system in place for weeds to be promoted to course 1.
So, yeah the author just wingin' it, and none of the plot developments make sense with the previous stuff.