JSP syntax is only valid in stream rules (e.g. Section, Control, Harness, Correspondence, Corr Fragment). It requires assembly to compile and execute the java. JS text files do not go through this process.
Can you describe your use case and what you are trying to achieve? There might be an alternative solution depending on what you need to do.
One solution would be to include a hidden text control bound to TemporaryProviderPage.Availability in the UI. You could add a class to the cell of the hidden text control allows you to easily find it in the DOM by selector and then retrieve the value from the DOM element. This would be outside the guardrails but is a potential solution.