Maybe this will clear up some ambiguity;
As per the above post,
Regulated routes and airports: As result of the 2002 and 2004 Reviews, two regulated route networks were created (Coastal and Northern Goldfields) and licensed for commercial operation to 31 December 2008 through a competitive tender process, along with one regulated route. Subject to the outcome of this review, the Minister may reissue licences
to the incumbent airlines operating those networks for a further two years and continue the licensing arrangements on the regulated route. A third network that is both regulated and subsidised by the State has a contract to operate to 1 July 2008 with an option for a 12 month extension.
The Coastal Network consists of the following regulated airports: Albany, Carnarvon, Esperance, Exmouth (Learmonth), Geraldton, Kalbarri, and Shark Bay. The Northern Goldfields Network consists of the following regulated airports: Geraldton (limited access), Laverton, Leinster, Leonora, Mt. Magnet, Meekatharra, and Wiluna. The regulated route is Perth to Derby (Curtin).
There is no reference to jet or turboprop preference except in the original review in 03'/04' where it states;
Offer Skywest Airlines a two-year exclusive licence to operate
services from Perth to Carnarvon, Exmouth, Albany and Esperance,
subject to providing ongoing services for Leinster and Leonora and
acceptable service standards and fare structures.
and
Jet route services between Perth and Kalgoorlie, Port Hedland, Karratha and Broome would not be subject to any competition restraint.