Questions about Dark Angels and Caliban

So this is gonna sound dumb, but I can't follow along with Dark Angels lore. From what I understand, the Fallen are Dark Angels which turned away from the Lion and the Emperor during the HH, instead following Luther. Lion and forces came back to Caliban, both sides fight and Lion goes into coma after fighting Luther. That's neat. But also from what i understand, there's apparently a wormhole that takes the fallen and throws them through time into 40k after Caliban goes boom (not trying to be funny as much as i'm just kinda dumb.). Now modern day Dark Angels hunt the fallen, blowing up allied forces who also find them and abandoning zones of combat to hunt down leads? How hasn't that lead to Censure, especially since the shit the Wolves got into so much shit for Armageddon?

Tldr: mainly just looking for a straightforward (or as much as possible in 40k) of their lore and trying to see how far off base I am from the truth.