Fox wouldn’t support Wallace because of his opposition to Supply Side Economics due to Murdoch .
I think that most Fox News executives would forgive George Wallace considering that he would have easily agreed with President Trump on nearly all the other policies that he proposed (with the exception of American Health Care Act).
He would have also opposed the Tax Bill .
If he opposed Reagan's Tax Cuts which had far more bipartisan support than Trump's did then he very likely opposes the Trump Tax Cuts as well. At the end of the day Murdoch (and previously Ailes as well) controls Fox News and would make sure Fox opposes him.