It reads like ので is tacked on to the end of the adjectival phrase describing 「新体制」, but I’ve never seen this kind of sentence before so I’m not sure. It seems like it might be a separate phrase entirely.
Does anyone have an idea of what function ので is serving here?
Mmm.The comma usage in the sentence is perhaps a bit deceptive – it’s very free with commas by Japanese standards, but it hasn’t put one after ので though I think they could have. I think this may be because it’s quoted speech and so the commas are indicating pauses rather than being used as grammatical dividers.