According to Dave Meltzer, WWE only brought Goldberg back so he wouldn't sign with AEW.

It's probably a smart move from WWE. I don't think Goldberg would ever sign with AEW, but if the money's right, he'd certainly consider it. Of course throwing a lot of money at past-their-prime WWE legends might not be a good idea in the long-term, even though he would get some eyes on the product.