I'm not opposed to retcons if they truly add something, plus are integrated well, even large ones. Seen a lot of bad retcons in fiction well after a franchise's formative stages (in those stages, retcons may either be needed -like BT's start- or things just aren't set in stone yet) so i'm leery of retcons.
So, Auriga gets added. Now, if it does survive the Fourth Succession War, will it be referred in the future? Will events where it logically probably should've played role get re-written in some form? Or does it subsequently get ignored?
"One and done" is no good.
As for geopolitics, that's human nature. 'Mechs are sine qua non of BT, along with ridiculously small armies and whatever else, and so get pass. But geopolitics and that shit is human nature, which decidedly isn't particularly different from real world, so at least i do hold them to higher standard (well, somewhat, anyway).