Can GCS commit today that Citizenship will remain at 5 years for you? And that counting will be from your application date? Of course not!
The TC might not rule until mid/late-December, maybe January if Christmas hols count (I’m not sure, see here). Then the President gets his say - will he bounce back to the TC again, or veto it? It will likely be January before we have any kind of certainty what’s happening… and then the AD will no doubt try pull some other BS if they don’t get their way.
So what makes GCS think you can commit to proceeding today? Are they really that stupid (or devious)?