If true, would that be in their own right, or on Flybe's behalf?
The recently dropped NCL by Flybe seemed to have loads that would be more suited to Saab 340 than Dash Delta (although dunno how poor yield was).
JS41 & SF34 seem to be suited to many ABZ routes, but they are no longer made - the a/c types used by the locos these days are too big for many ABZ routes, especially if they are competing routes. In hindsight daily LPL for example on a B738 was probably ultimately too much.
How about Cityjet & Aer Arann - have bosses at ABZ talked to them I wonder?
I suppose, ultimately, many see ABZ as too far away to be worth serving, plus the added fuel costs would make it even less appealing - perhaps BAA bosses are running around in ever decreasing circles trying to attract new operators/routes (especially with the knowledge that operating into/out of Dyce ain't cheap.