I don't believe there is an issue actually.
A tag can be created without a GC-Code. I made one myself this week actually (linked in the FAQ).
I am fairly sure a tag can be created for a GC-Code that doesn't exist (is unpublished) as well. The only thing that will happen is that the cache name will be a question mark. At least this is how it worked from the beginning, if it's not like that anymore, it will be fixed.
So the expected flow will be something like this:
- A geocacher gets a great challenge idea.
- The geocacher registers a geocache and writes the description.
- The geocacher writes a challenge checker, or asks someone else to do it, providing what details is needed (requirements), preferably a copy of the cache description.
- The geocacher (or the helper) tags it to the GC-Code the geocacher has, but isn't published.
- The geocacher adds the link to the checker in the description so that it's available for the reviewer.
Now, I hope it's obvious that Project-GC have had some discussions with Geocaching HQ about the whole Challenges + PGC checkers thing. We have not discussed the details of the work flow yet, but I see no reason to that it will not work more or less like I described above.
As Groundspeak has said themselves. Not every detailed is ironed out yet, they/we are still working on details, but in the whole we know where we are heading. Basically they are focusing on the future guidelines and Project-GC is working on making it as smooth as possible for everyone to handle the checkers.