The case that brought about the SCOTUS decision involved a shopping mall, not a theater.
A local ordinance is not the same thing as a term of entrance to private property open to the public - apples and oranges.
I assume you're talking about the PruneYard Shopping Ctr decision. Note that it doesn't demand a state act foolishly like California--it just said that California could be nuts. Many states have come out and clarified that they will respect property rights.
Secondly, many of the reasoning points behind that decision do not apply here.
IOW, the SCOTUS decision is irrelevant here, confirming that the shopping center example is spurious.
IANAL.