I wouldn’t call a loss of both FDs, or even both FMGCs, an emergency.
So, you're taking off from Innsbruck on a PRNAV SID, in IFR conditions. You lose both Flight Directors.
Do you:
1. Say to the other pilot - "Damn, we can't legally do a PRNAV SID without flight directors. I'm going to fly straight ahead until we can get vectors.", or
2. Say "It's an emergency, I'm going to follow the path on the Nav Display, and I don't care about the letter of the law." ?