Then the bands whether they are loosened will stress the sap flow. Usually one season is all the stakes and straps is needed to be left on for.
If the tree was still to topple, then a triangular pattern of arbor stakes should have been used.
Take those bands off and allow for the tree to callus around those damaged areas. Remove and damaged or dead bark. Left on the tree will not allow water to exit those areas. Also, these areas will hide invading insects.
If this tree is truly strong....it will survive and callus up around the problem.