It has got to be alot of work to add new armor. Don't really see why they wouldn't do it now since it's something that needs to be added anyways.
The difference between the AF for the original and Zilart jobs and the AF for the ToAU and WotG jobs is that the later jobs got significant bonuses on their armor, whereas the first 15 job classes got AF that really doesn't make a lot of sense in today's Vana'diel.
It's no secret that SE releases things early and then watches the player response.
My belief is that SE holds on stuff like this for as long as possible to be sure that the players are holding on to generally accepted sets of rules when using the job classes. It took them a long time to give DNC/PUP/COR relic gear because they were debating on where to put it.
However, a precedent has been set, and SCH and DNC should not be waiting nearly as long as the ToAU jobs did.
I'd much rather see useful Relic gear and AF+1/Relic+1 by waiting an extra 6 months than I would have **** gear now.