Could you please spell this interpretation out for me? I'm unsure what to make of it.
So first, MS wrote that they had "record breaking sales" and we are assuming by record breaking they are comparing it to last year since the Xbox One has only had 1 black friday period prior to this one that just passed.
The asterisk clarifies that the period is between Nov. 21-27, and generally when you compare things to announce that a new record has been reached, you would need to compare two identical periods. For example if you said "Sales in November were record breaking compared to March" that would make absolutely no sense.
So we can only assume that they are comparing sales between Nov. 21-27, 2014 versus Nov. 21-27, 2015.
The problem with that is Black Friday was on November 28, 2014, but it was on November 27, this year, so the "record" that they broke seemingly didn't include Black Friday which would account for a huge amount of sales, moreso than all of the other 7 days prior combined.
tl;dr version: MS apparently compared a week of sales
including Black Friday this year versus a week of sales last year
not including Black Friday sales. Of course it would be recording breaking. So while technically they are comparing two identical periods (based on date) it would be misleading. If Black Friday 2015 really beat out Black Friday 2014, they should have just stated that instead of Nov. 21-27.