Just to update this... I just bought a new rear rotor from EBC that arrived a few minutes ago. Definitely doesn't come with an ABS ring on it. So, I popped on here; found this thread; started sweating; gathered myself, a hammer with claw, and a shop rag. As carefully as I could, I pried off the ring. I haven't yet installed it onto the new rotor, but I wanted to update this to reflect that it does occur and it can be dealt with.