I don't think it was, at least not that black and white. If the community really was that split the project would not have survived for 20 years. Surely we would have seen a fork where the involved factions split off.
I think this is a very vocal minority in play here. From my understanding these changes did not come from any of the core contributors but rather from activists. The used divide and rule; if you don't sign off on our political documents you are with "them" and we will let everyone know what a horrible human being you are.
It seems the loud voices about how bad the CoC is aren't actually kernel devs...
But there is atleast one known kernel dev who spoke up about Linus' behaviour, and eventually just quit developing for the kernel.
edit: not to mention those who don't want to touch the kernel because of his behaviour. one guy said the only contributions he makes to the kernel are for his employer. if it wasn't for that, he'd not touch it.
For the 30 years where it was one project, the community was split? And now that it has been forked because of outside political issues being forced in, that's the same amount of split as the last 30 years?