Dean Malenko, Booker and JBL came forward to John Laurinaitis and urged him that he should be signed immediately. London even came forward and spoke to writers asking them if he could work with Mistico.
When Mistico had his tryout, however, he forgot to mention that he had signed a five-year contract with CMLL. He still has several years remaining on his contract. WWE lawyers decided that the only way to get him in WWE would be to negotiate with CMLL. CMLL is in no way interested in working out a deal.
So the likeliness of seeing Mistico in a WWE ring in the future is very slim.