We don't know if the hockey rink will pay property taxes because the building will be owned by the tax payers. Right? It's bonded with the property/business owners carrying the paper. If the property is owned by the Town I'm going to assume $0 property taxes. There is a dent for ya.
One factor we do know is the mall is paying taxes now and if it closes someone will purchase the property. I don't think a prime piece of property would sit long. Look how busy transit/main are at that location. Once purchased as long as incentives are not given the new owners would continue to pay property taxes where as the town owned hockey rink would not.
One saving factor the Galleria has is out of town shoppers. I don't think the area could support the mall and others if shoppers from out of the area didn't visit.
Why pivot to something we have seen in the past not work? Government subsidized sports complexes for the most part do not generate more business around them.