I am more inclined to believe it is purely social, but we never know.
As much as I'd love to stir a 'Newey to Porsche' rumour, its likely simply this. Newey didn't wan't to go to China, likes WEC, and fancied going and supporting a mate in his first race in a new series. If you can't use your position as F1 Aero God to blag a free ticket to a motorsport event then that can you do