Its like pro-NFL team ownership.It doesn't need to publish to enforce its copyright.
As far as trademarks are concerned, there is all this on DriveThru - - | Greyhawk | AD&D 1st Ed. | DriveThruRPG.com - and WotC is currently litigating to try and argue that these sales are sufficient to establish its rights as TM owner in relation to the material it is licensing to DriveThru.
Its best when its simple.
Ed Greenwood sold his rights to TSR for what? $5 grand. Hes been incredibly decent about it.
Wotc has rights to Greyhawk, but not Gary's old stuff--Gail is holding onto that until she dies and her son (not Luke or Ernie--shes made sure that Gygax mag could never be produced for example--will get to decide that fate..that fella has my sympathies..).
Anyway, yes there's plenty of GH stuff on dtrpg, et. The only thing left to do is ruin it. It is a completed setting already. Selling us an advanced timeline with already-obsolete modernisms Ohhhh..yea..no..not..excited.
Give me a 1-page sheet of rules updates that say (among other things), 'You're the DM. You can do what you want.'
The biggest takeaway from Riggs' book's statistics: settings books were the wrong start, lost shittons of money, and divided fans into FR or GH camps.
IF adventures that shoehorn into multiple settings are the future.
What will that look like for GH?