OK, rather than rely on my (clearly poor) memory, I will just cut and paste the rules from 2016 from Mike Basman:
Qualification for the 3rd stage of the Chess Challenge, the Northern or Southern Gigafinal is as follows:-
(a) winning the title of Supremo or Suprema in any of the 24 sections from U7 to U18.
(b) scoring 4 points out of 6 in your section of the Megafinal (Please note that players scoring the same points as a Supremo or Suprema but failing to win the title on tie break, only qualify if they have scored at least 4 points out of 6.)
So this year obviously (b) needs to change to 3.5 points for ages U12 and up. But the rules clearly state that if you score less than the qualifying score, you must win the Supremo/Suprema titles to advance. And I have had no notification that these rules have changed.