Well, there's about 2 ways you could have a leak at basically every seal on the engine as stated in your post.
1. The PCV system is essentially nonfunctional, you have a ton of blowby and are overpressurizing the crankcase and have blown out the seals.
2. You have a leak from one place that is coating everything else and the dealer is too incompetent or lazy to figure out where.
#1 would take a lot of things to go wrong at 50K miles, #2 seems far more likely. Also very likely that since the oil filter is in a terrible place for doing oil changes and it is almost impossible to remove without bathing the front side of the engine in oil, that it may appear as a leak. Particularly if the one doing the oil change is not very diligent about hitting it with a rag during and after the process, and even then the cardboard I park on will get a couple spots over the next day or so.
I'd try a second opinion at another dealer or an independent shop.
2016 Traverse (KIA @ 25k miles)
2010 Traverse (traded at 117k miles)
2016 SS Sedan
2001 Trans Am