Yes its ethical to support Impact Wresting. When the Hardy's contract came up for renewal Anthem had the right to resign for what they felt they were worth or not sign them. Just like when the Hardy's became free agents they had to option to sign with whoever they wanted. Things do not always work out. It's business.
If Anthem owns the rights to the "broken" character they are doing nothing wrong.
My best advise don't over think it. If you are a wrestling fan just enjoy it.