I don’t know when exactly Gavin posted that, but Jorune wouldn’t have made the thread much later so I expect it would have been within a few days of that thread.
TimeTravelForum.tk was the ORIGINAL time travel forum. From what I was told in my TimeTravelForum.net days, Gavin had abandoned the site and none of the moderators could do anything - Banning, updates, changing forum structure, whatever.
Phoenix and jovial_kitten decided to branch off and start TimeTravelForum.net, bringing along people like JedyStryker, sosuemetoo, CaryP, Dadof5 and Satan as moderators and new admins. There were a bunch of others I can’t remember just now. Gavin came back, saw what had happened and did everything he could to prevent the fork of his own community.
On the one hand, Gavin was in college and had apparently been suffering from some kind of injury, so his free time to run a time travel forum would have been limited or non-existent. On the other hand, I do remember folks talking about having tried to reach out to him for quite a while before they created the new site, so the truth probably lies somewhere in the middle.