There are watches for young people, in the PP family.
Come to mind models like the Aquanaut, the Nautilus ( the Chrono being, in my opinion the one which looks the younger model ), the 5070 ( especially the P ), and even the 5140 P.
About Calatravas, which is your main interrogation point, maybe PP can play on the color rather than on the style of the watch?
Let's imagine a blue dialed Calatrava, for example. If it works for the 5140P ( which amazingly has waken my interest up for the 5140 ), why not for a Calatrava?
White metal, blue dial...That would be cool.
I don't believe in some watches like the VC Quai de L'Ile or the RM 5 / 10 fro a brand like PP, it would be too weird looking, in my opinion, as it is obviously not PP's Credo.
But playing on the color of the dial may do it!
Best,
Nicolas
PS: I recently saw a 5196P on a 20 years old guy who was wearing a pullover and a paior of jeans, it was perfect!
" Elegance is an attitude ".