Hmmm, I just tried that 'select all and drag the rightmost edge. It only extended the rightmost clip. Is that really supposed to work? I could use that edit if it did. Could you try it and see if it works for you?
I'd guess that a "Group" hadn't been created, and the phrase "group of events" was only referring to a possible selection of Events, rather than an actual "Group", as used in the Vegas Pro terminology.