It gets even confusinger, as LF is now hosting a CLS at LinuxCon events, which has been renamed Open Source Summit. I have asked Jono about whether the event at OSCON is also still happening.
As for the renamed Collab Summit, I don't know how much confusion that will cause. I know the name change was meant to clarify the purpose for the conference, which is a meeting place for leaders in Open Source projects. CLS has a lot of crossover with Open Source, but many of the communities we discuss there are not open source projects at all - some of the most dynamic discussions I have been in are about communities around proprietary products.
I think right now we need a bit of guidance from our fearless leader