The Abyssal attacks have created a new status quo in their favor. In the future attacks, they'd have better starting point advantages.
But overall, the Federation didn't consider this war as a great loss. For one, even if the humans saw many casualties, the Abyssals had nearly equal deaths.
Originally, Humans lost a few million soldiers more than Abyssals. But with Varian sweeping thirty planetoids by himself, the gap was quickly closed.
And secondly, even if the Abyssals did occupy some strategic locations in the planetoids and in rare ocassions, occupied a planetoid itself, they didn't gain any breaking edge.
Mercury, Venus and Earth were still pretty much safe.
Mars, which had the potential risk of falling, could now be considered as the planetoid with the planet with best defenses.