HR is on every layoff call this is standard procedure for legal reasons. To confirm this kip stated on monday that the people not beong retained will be speaking with their RD and HR.
You can find out who is on your call or who was sent the email, by asking around. Once you talk to enough people you can put it together. Its not that difficult. I have spoken with at least 50 people in 3 regions. The majority of the people are on their regional group call. There are about 10-15 people on individual calls all scheduled proir to thier regionals group call. They know they are on individual calls because the rest of their region is all on te same call. The individual call times vary as they have to make each call individually obviously.