I wouldn't mind this. I mean, first, them putting the ward there means they know you're there. You getting the bonus isn't wasted, you now know they know you're at wraiths. Second, it means they didn't put that ward somewhere else. So either mid is wasting an extra 75g on a ward every time you go to wraiths, or they don't have somewhere else warded. Finally, it isn't exactly risk free, especially if you still have mid tower up... Perhaps you should be throwing your own ward at the back of your red and collapsing on them when they try to ward your wraiths.
Anyways, I'm arguing because I like it at raptors (obviously). I play blue dependent junglers, so I start blue. Which means I do red second, and raptors before my first gank. It would be less efficient for me at wolves. More importantly though, this may bring balance to the dragon/Baron inequality that used to exist, and switching with wolves may bring back and increase that inequality.
What I mean is, blue has easier access to Baron. Red has easier access to Dragon. With the position of wraith camps, the team with harder access has closer access to vision via wraiths - so they can grab wraiths and run by the pit and clear any wards. If you put it on wolves, I'd expect purple to have a large Dragon advantage and blue to have a large Baron advantage.