This is a followon task to some of the tangential commentary in T144475: Make it possible to create json pages in the module namespace, specifically T144475#4894433 and T144475#4898734. The objective is for both modules and gadgets to share the same data without modules needing to suffer the load-penalty of mw.text.jsonDecode alone.
Maybe this task is trivial per Lego's comment and can be done in calling code already. I don't understand the infrastructure enough to know whether it is or isn't.