That would be cool if Toby gathered all of the H-B and they went on an expedition to free the H-B homeworld.
I like this idea... It's funny how nothing was mentioned about the H-B homeworld after the war... But I have a theory...
Remember how the Arn basically almost went extinct, and were driven to the deep valleys by the Cataclysm? And how they had to grow the super trees and create the Hork Bajir to maintain the ecosystem?
But the war devastated that delicate ecosystem, even within the lifetimes of Aldrea and Dak... The planet was a disaster area, with the trees being destroyed left and right (either as collateral damage, or deliberately by the Yeerks) and the Arn were herded into the awful (non-environmentally healthy) mining camps...
And don't forget about the quantum virus, that rendered a sizeable number of the vallies uninhabitable for H-Bs... Yes, the Anis went there with Quatzy to "start a resistance" and try to take back the planet, but seriously? There wasn't much planet left to take back... I'm guessing that pretty soon after #39 the Yeerks all but abandoned the planet anyway, because the resources that they could still acrue weren't worth the risk of losing people and ships to an Andalite attack...
I would imagine that Toby understood that the Free H-Bs on earth would have to stay there... in their new home... And rather than retreat to their decimated world and withdraw from the other civilizations, they could carve out a new life, and new respect for themselves...