It seems like it should all be automated. Some scientist generates a mission request for the JWST techs. If accepted the mission is added to the timeline with all of the metadata the original scientists had in their proposal. Stuff like the area being imaged, the sensors in use, duration of capture, etc...

Once the data is collected and downloaded it is added to the catalog with all of that metadata attached. Then it's a matter of opening up that catalog to the public, although I'm guessing the downloads will be quite sizeable so the bandwidth could be an issue.

The trick to making this work is to integrate the publishing into the workflow so it doesn't require any additional effort on the part of anyone.