I think you are confusing things, it isn't Knott's that has had questionable practices during the entire pandemic, they have made sure they have taken care of their employees (keeping several employed even when the park was completely closed) and their guests alike. They also followed through with every promise they made during the pandemic, something that Disney did not do. Disney broke almost every promise they made during the pandemic.
Unions do not keep anyone safe, unions are outdated and useless. For example, the unions right now are trying to negotiate with Disney to get the same starting wage that Knott's is already offering. Knott's has shown how to reopen safely throughout this mess, even to the point of going overkill on their safety measures at times.