edited to try to differentiate between how it used to work and how it works now.
Not sure if it is clear, but he means points, not races. In the past you could run any race you want, but you were not eligible for regional championship points. Which technically should have been called divisional championships, since they were divisional championships made up of points earned at regional races. Which seems to be what they did this year, rename it "Division Championship", almost got to "divisional championship", but not quite, maybe next year.
But for this year:
Per my reading, major races don't earn points toward the division championship series. Just the 6 regional (there's that regional word again) weekends count to the DCS, a total of 12 races. 12/2+1 = best 7 finishes.
Paragraph 6 is quite clear: Everyone now earns divisional points. If someone runs majors and even qualifies for the runoffs thru majors, that person is still eligible to earn divisional points and even "win" the divisional championship series. In the past the points earned at each event are based only on drivers within GLD, out of division drivers are ignored, so you could finish 4th and still earn 1st place points by being the first GLD driver. I don't see that explicitly mentioned in this year's rules.
Also note that there is a difference between earning the right to go to the runoffs thru the DCS and winning the divisional annual championship since there are regional races after the runoffs. So drivers A,B,C could be in 1st,2nd,3rd place when the eligiblity for the runoffs is decided, but driver D could earn points after the runoffs and win the divisional championship. That's not confusing at all, is it?