Join Date: Aug 2009
Location: Portland, Oregon
Nah, they repopulated Armageddon when Angron and his merry fellows had a party there.
I imagine they cleared all signs of the battle and resettled it. The galaxy may be vast, but habitable planets are still a rarity.
Or possibly they turned the planets into some sort of giant memorials. Honoring the brave loyalist marines and decrying the Chaos ones.