From a retailer:

Viewing a retailer order sheet, Bretonnians are no longer able to be ordered from Games Workshop at this present moment. Following the usual cycle , this indicates that there is a new rulebook on the horizon with some new models to come. We assume this would be in the November/December release slot after the Inquisition Skirmish game is announced in October at Gamesday UK.

Distributor sources verify the upcoming WHFB release shipment, described only as "a human race", with but would not confirm a release dates.