Council property manager Mike Hibbert said a "handful" of appeals had been lodged in the Environment Court against the plan change.
Mr Yovich and his supporters argue the council failed to adequately address the negative economic effects of the plan change on businesses in the CBD.
"The decision is inconsistent with stated council policy to maintain and strengthen the city centre as the primary centre within the district for shopping and employment," the group said.
In his submission to the commissioners last year, Mr Yovich said a hotel or a conference centre might better suit the Okara site, with its elevated topography, rather than retail stores. "The lack of sustained use for recreation of the current site rationale being used to promote the plan change is part of a self-fulfilling prophecy," he said.
A Northern Advocate survey of the CBD precinct in late December, including 10 streets and the Strand Arcade, found 40 empty businesses, with Rathbone, Cameron and James streets the worst affected areas.
A number of retailers had claimed that the main challenges included menacing teenagers, a district council that actively encouraged business to the bulk retail development at Okara, and inadequate parking, including coin-operated parking machines. The Environment Court has not set a hearing date.