It was brought up that some api jars like bean-validation need to be updated to include a module-info.class, but it was unclear what requirements are needed to verify this. TCKs do not run with modules enabled. I just did a basic test of accessing the java.lang.Module information for a class loaded via the class path from a jar with a module-info.class, and of course the class was loaded from the unnamed module.
It seems like the baseline validation of module-info.class for api jars will have to be some check for existence as part of the specification pull request review. This is something that can be added to the existing automation work.
If other projects want to add additional TCK tests, I suppose they could, but since it is not a requirement for implementations to run with modules enabled, it probably won't work. For the next platform call we need to clarify exactly what module-info.class validation is required, and whether projects like bean-validation can simply put out a service release that includes only the api jar, no TCK and obviously no spec updates.