We see no reason the thread can't continue with Ossanlin, Claxter, and the characters who are still around. We see no reason why other RAFians cannot be contacted with invitations to participate.
Alternatively:
Box the RP. Put it on a shelf, philosophically, and just leave the thread standing, functionally. There have been a time or two in the past when very old RAF RPGs were revived by new visitors, or by former participants having a bout of nostalgia. It's not common, and yeah, this kind of decline does typically signal the death of a game, but that doesn't mean that nothing about the game is recyclable. It's a narrative left standing with the doors open, waiting for new blood to show up.
For us, coupled with the general intensity of offline life, we're just heavily fatigued with this particular story universe right now. We love Animorphs, but our literary tastes are pulling more toward urban fantasy-horror, metafiction, and the stuff which leads up to impending NaNoWriMo. Space opera stuff has been trying its hardest to take a break from our attention, and we're finally letting it succeed at that, because it feels kinda' yucky to leave a good game waiting on us, even in a minor capacity.
The only real flaw in this game is that the participants, arguably collectively the most mature / prolific / dedicated RP'ers on RAF, are also some of RAF's oldest and most offline-life-entrenched members, with the least time, energy, and attention to invest in a game. The hardest bit of it is when the game starts to feel less like a leisure activity, and more like another obligation which one strives to uphold responsibly, for the sake of the other players. It gets forced and, as you say, becomes less organic. We don't know about anybody else, but we prefer to offer a game the most graceful death... or coma, as the case may be... possible. Leave the doors open for a potential-someday infusion of life, but turn off the conveyor belts that lead to the doors. Rest. Turn to other things, other stories, for awhile.
Anything affiliated with the GESB is inevitably a little bit immortal. The thorns might grow up around her, but Sleeping Beauty won't get any older or uglier while she waits for the cavalry to show up. There is nothing dishonourable about To Be Continued, or Until We Meet Again.