I don't know how reliable this site is (maybe it's just their opinion? rather than actual info), and if the german text filtered through english translate makes it right, and it is couple of weeks old, but it seems to say that Rebellion didn't go to the July test because they feel
AER is running smoothly and additional data is not required. Kolles on the other hand had new aero components, and obviously their car is bit of nightmare all things considered
http://wec-magazin.de/bykolles-laess...-unterkriegen/
For Rebellion that'd probably mean no running since June