My understanding:
A query was raised in May/June time that average points is not fair, as win/lose games have different maximum winning points in comparison to win/lose/draw games. The League met in June and announced to all clubs that if no win/lose games were off due to COVID then they would stick with average points (at this point only win/lose/draw games had been off due to COVID). If there were both win/lose and win/lose/draw games off due to COVID, the league would change to percentage points for fairness in terms of points available in the two formats.
Prior to the final week of fixtures, there had been no win/lose games called off due to COVID. However, in the days leading up to the final round of fixtures, Willington called their final game off due to COVID. This meant NEPL1 would change from average points to percentage points. This change meant that Newcastle finished ahead of Castle Eden (rumoured to be by 1 point) and were therefore promoted to NEPL.
Castle Eden then lodged an appeal. I believe the appeal was that the league should not have accepted Willington calling their game off due to COVID (There have been rumours that a lot of their first team were at a music festival). The league however didn't really question other games being called off for COVID earlier in the season, so I don't see how they could start questioning these things.
I was told yesterday that Castle Eden have now got solicitors involved. This has all got a bit messy and in my view, everyone was aware of the rules regarding points in the event a game is off due to COVID.