Shedim are not Horrors. However, they are a harbinger, of sorts. Basically, mana levels are still too low for them to cross over without a massive rift to open the door for them, and without a host, they starve from lack of mana, same as with the bugs. When mana levels are high enough that they need not have hosts in order to remain here, then you will start needing to worry about Horrors crossing over. (Though that says nothing of Horrors who are already on this side, or trapped in 'between' places, like alcheras.)
And no, the Universal Brotherhood does not exist any more. After Chicago, people rewrote the idea of 'extreme prejudice' when dealing with the UB chapterhouses around the world. Now, did any UB insect shamans escape? Of course. But the organization itself was put to the torch, if not blasted from orbit. As for other 'charities' carrying on that work, everyone knows the signs, now, so any group that starts looking like they're infested is going to have runners, at the least, checking things out, if not Firewatch teams.
But more to the point, the bugs just aren't working together any more. They naturally hate those of different kinds, or different colonies, and have been seen fighting eachother on multiple occasions. So you may get a local charity or group to act as a front for, say, a Wasp colony, but you're not going to see a national or international organization with multiple types of bugs all working together, not unless something major happens.
