Theories about the remnants. *possible spoilers*

One guy on youtube(Hotnotmeh) had this nice theory. What if the remnant were originally a species from a planet that is hostile to most life, like a volcanic world or something, and they made and programmed this technology to terraform planets in the galaxy to their liking, but then something happened to them, and now their machines just continue doing it mindlessly after theyve gone, hence we have the "Scourge" seemingly changing planets. The story might involve us finding the source of stopping the scourge in this part of the galaxy, thus saving the planets were about to colonize.

I added a warning up there, so people who dont want to be possibly spoiled can avoid this thread.

This would actually give the kett a motive too. What if they named the phenomenon the "scourge", and the reason they are invading is the same reason we are, looking for new worlds, because the scourge is taking out their already established worlds, In effect they are running away from it.

Actually given that we have a Halo 4 writer for the game, there could be several things we have already seen in that game, unfortunately repeated here a little differently (halo 4 spoilers ahead):

- the kett are a highly religious (like the covenant), they are lead by archon (the prophet of truth)
- the kett think the remnant(forerunner) tech is sacred, but they dont know its actual purpose, in this games case that it is actually whats causing the scourge.
- the kett are running away from the scourge, like ancient humans were escaping from the flood and invaded forerunner space(in our case its Heleus cluster)

I mean Halo 5 already kinda used the ME3 control ending like stuff, with huge machines forcing peace in the galaxy with a seemingly benevolent AI in charge, and the created rebelling against their creators that whole shebang.

Could it really be we get these similar plots again, this time reversely?