Do the retainers dissapear from the wards after a certain period of player inactivity?

Always wondered 'cos on the Gysahl server, in the Gridania wards someone has set up a full row of Lalafell that all sell crafting equipment (hammers, saws, needles etc.) and they've always been there.

To be honest it must have taken them ages to set those retainers up like that, it's quite an amazing sight, but also incredibly usefull to other players to be able to get hold of different ranked crafting equipment so easily. ^.^