White label is essentially just a term they use to signify they are operating routes for another operator, possibly in Flybe colours but as with SAS, possibly not. The 4 ATR's will be painted as SAS with the intention that they will only operate those routes and the pilots recruited will be trained on the ATR and given there own, locally adjusted, terms and conditions. The initial management and technical team will be Flybe pilots, mostly ex-ATR rated guys and then once enough new people are trained the fleet will be operated exclusively by the local Scandanavian crew.
I'm not sure when recruitment will begin or who will conduct it, but with our own HR department currently unable to keep pace with the Dash recruitment needs I would not be surprised to see some external company take over that role. If operations are to begin in October I would be expecting type rating courses in Aug/Sept maybe.