By the looks of things the change was mostly about the PL guys that were dealing with renters got fed up by the drama caused when some renters would take sov and feel that they were now boss of that system and could tell other renters to stay away.
Event Horizon seems to be pretty much untouched by this. Not sure why but i guss for now they are considered a pet alliance of PL and i dont think they are paying rent. Things could still change, but for now i am willing to risk a few ships.
I would still be ready to move my shit out on short notice but tbh this is probably something one should be prepared for in 0.0 as you never know when someone resets all standings or some other alliance gets bored enough to invade.