I do have to address the issue if we allow this event to take precedent. The reason we have the activity rules at all, referring to public posts, is to ensure that beast hosts are available to find in RP. At least that's what I see as the "spirit" of the rules as you refer, Eric.
If we allow NPC posts to be considered activity, then what's to stop someone from demanding the need for an IC hunt, refuse to allow orchestrated hunts like with Sabu and you, lock themselves away in a pocket dimension, and continue to post forever as NPCs to keep up with their activity.
There are no rules that require you to accept a manufactured hunt RP, so now as a challenger, you're forced to somehow gain the knowledge that this person is a host, assuming they've even told another player IC that they have the beast. Then, if you can even make it that far without RL months of time spent trying to travel from one village to another and actually gain the information without meta-gaming your way, you're immediately stone-walled by the fact they are camping inside a pocket dimension with no way to access it. Because then if we allow access to peoples pocket dimensions without their consent, we're opening a whole new can of worms.
This is a situation I don't feel like we should simply let pass, because like I said, it will set precedent for future hosts.