Places/locations/ideas from old content showing up in the new canon doesn't make the old content canon... if merely makes those places/locations/ideas canon. When Thrawn appeared in Star Wars Rebels, that didn't make the old Timothy Zahn novels canon again. It just created a new, canon version of Thrawn. Darth Bane being in The Clone Wars didn't re-canonize old Darth Bane stories. Or the planet Malachor in Rebels. Or the mention of Life Day in The Mandalorian. And so on and so forth.
Same principle applies here. Maybe some locations from old Dark Horse comics are canon, since they're on the map, but that doesn't make the old stories that were set on those planets canon.