Yep, confirmed.
Thing is that after you zone, you need to disband the group completely, invite the PCs again, then add the bots. For some reason, if everyone zones, it thinks the second PC in the list is the group leader or something.
So adding bots to the group results in them dying on the spot. It was rather funny when you have a macro to do mass bot invites and see all of them die at the same time, hehe.