At least for 1970, the shop manual will confirm that the temperature controlled ported vacuum switch was used for only one purpose. It switched distributor vacuum advance from normal ported carb vacuum over to manifold vacuum when the engine overheated. This was done to increase idle speed so the fan and water pump ran faster to increase cooling.
Some cars also had the dual advance distributors which applied manifold vacuum to distributor retard. This was done to retard timing at idle to more completely burn the fuel for emissions. This makes the engine run hotter. I don’t have all the specific vacuum routings for the different engines, but don’t believe the retard vacuum was ever routed through the temperature controlled ported vacuum switch.