Is there

[C2K]

Yep they should always be replaced including the nyloc

Sorry but no. You can do that if you want to be super safe and super anal but that's a grade 10.9 bolt and you've in no way compromised its integrity with the pathetically small Peugeot torque figure. If the threads are shagged then yes, obviously.

Nylocs yes, but then engineering studies always prove inconclusive as to whether it degrades or not. I've re-used them before with no issue.