Several things.
1. The ability to take another's body involved Darkness in BBS, so it kind of makes sense that it was originally a technique of the Shades (faster to type out than Darknesses and refers specifically to these six.)
2. The Lore that originally Darkness was originally a multitude of physical beings was already established, but now they clarify that they came together in an attempt to win the war as formless beings and now there are six Shades, two of which are already introduced to us. Also they are quickly losing sentience and need bodies to maintain their sense of self.
3. Someone said earlier that "six is an odd number, so maybe there are actually seven and MoM is the Seventh Darkness" which is personally too much of a jump to make over a thematically mismatched number, for all we know the Shades have 111 units in them and then that would be a thematic tie. Or it could just be a number without much weight behind it for once. While that might be a bit out of character for the series, I wouldn't say that it is unlikely.
4. Scala could have been populated by the refugees from Data Daybreak, but I won't go too far down that logic simply because I want to focus on other things.
I really enjoyed this update. Seeing as the team that upkeeps the game and does the animations are so small I'm happy with getting the level of detail we are getting in things like the consoles correctly displaying things that happened to the pods and such. I also feel kind of bad for them because it's probably more trouble to animate the big scenes than it seems. Actually as someone who has some knowledge and experience with game making; even with pre-baked assets in 2d it's pretty frustrating to make cutscenes the exact way you want them.
Wait, so if the data Daybreak Town was created to be a back up of the real Daybreak Town before the war happened and that there it's being theorized in-game by the Dandelion leaders that Strelitzia and themselves have data versions, wouldn't that imply that there's data of everyone in Daybreak Town, including those that didn't end up being Dandelions?
...Now that you say it, probably.