I've been thinking about this a bit, and I'm wondering if the reason you won't be able to zone with a leet is becauseAO doesn't support NPC zoning (EQ doesn't either, for that matter). It might be too much of a programming task (and would detract from other areas of development) to implement such a thing when the line is only meant for amusement. One thing to keep in mind is that leets can pretty much be found in every zone, so finding a new pal shouldn't be *that* hard.
Perhaps Funcom will support adding "adopt-a-leet" bins in some of the more popular indoor playfields (Reets, Rompa, Baboons, etc) so that having a friend inside will be possible?