Patrick,
So, not all nominees are invited or choose to wear Chopard.....
A more plausible hypothesis is that Chopard is close to the players so they know what or whom are trending. But that does not explain how completely unknown and unexpected winners were wearing Chopard at the time of their anonymity.
Finally, there is a sprinkle of Luck as with all Oscar awards; that would explain why some great actors have never won an Oscar or have to wait until they are almost dead before a Lifetime Achievement Award...the true Kiss of Death.
Regards,
MTF