This is kind of silly, and so are the people calling it jingoistic, but it’s no big deal. But I think that we replace “going to the john” with “going to see a Frenchman about a horse.”
I’ll go out on a limb and assume you’re serious. No, this is the exact opposite of PC because the substitution is intended to show contempt (regardless of whether the French care). PC is intended to eliminate offense. You might as well say “Dubya” and “Slick Willie” are PC.
For real live PC at its absolutely silliest, see the following.
I’ll say it once. That’s flat out one of the stupidest things I’ve ever read. And France is a democracy. At the moment. Can’t say what’ll happen if the EU is ever completely implemented. And by the way: 
Pretty offensive, but the bilingual pun is wonderful!