"HOLY TIME MACHINE BATMAN! it's 1973!"
https://youtube.com/Hazzbazzy
Tested it again just now, and instead of what I did last time when I ran through the gates to Arathi Highlands (which was what made her reset last time) I instead waited out the bribe duration before the zone change and she despawned. The same thing happens when you try it with the Battlemasters.
The only thing that still seems to be working, and occasionally at that, is the Steamwheedle bruisers in STV.