I'll agree that the term gets overused - you still see people talk about "panic farming" for JTR and she's been out for ages. If you want a legendary, you should just farm for them until you're ready, regardless of when their event is due.
The first Revan run was definitely a panic farm though. There's no way you could reasonably have gotten him the first go around without spending unless you were taking #1 in both arenas every day. And if you were doing that, you had probably already spent quite a bit in the past.