They've hinted that this would happen since the release of WoTG
As for how it works I believe the more ppl that releases bottled pixies in the past, the more common they become in the present. Something like that.
this is basically how it goes..... on phoenix, a buncha jp's did a night or two of bottled pixie runs... and then they really started showing up alot more... not nearly what it is in the past yet.. but it is getting there
Someone should organize a mass liberation project of having masses of people kill quadavs in the past for bottled pixies and free them at their spot in Grauberg. Unless of course there is knowledge of a pixie "cap" in present zones.
Just an idea.
Eh. For what it's worth and for those who are bored as hell with time on their hands...AND would like to contribute to their server.
Yagudo High Priests outside of Oztroja[past] drop a Bottled Pixie 100% of the time. They aren't terribly hard to solo on a solo friendly job (I had no issue as PLD/RDM, PLD/WAR and PLD/DNC, as well as BLM) and are easy to pull behind the rock near its spawn so no link/aggro while you kill it.
Only issue being it's a little ways out of the average way, and then the run to Grauberg gets a little irritating, in addition to the item being R/EX. Not like you can kill 30 priests and go liberate a small army at one time. :/
On Valefor, the pixies are all over the place in most of the low level zones in the present. It's awesome having a pixie nearby when you're leveling in the dunes. Raise please!