As I tried to prepared a witty response, I couldn't help but to fall into this mystery of Wolverine's... Lil' Berserker. To wit, I discovered that what my friend had stumbled upon was true, but it was only the tip of the... iceberg. I was going to say 'iceberg'!
First, we need to have an understanding of Wolverine's healing factor. While super charged and fast acting, his healing factor isn't a remedy for the ravages of time. While it's quick to heal a fresh wound, the factor isn't constantly working to heal Wolvie's body. His cells die off just like anyone else's, creating that awesome hair style of his and keeping him from looking like the walking tumor that is Deadpool. I suppose this is just a roundabout way of saying that wounds received before puberty (when the factor kicked in) wouldn't be healed. And by wounds, I mean circumcision.
Speaking of, the next step in this horrible journey is to research the history of circumcision itself. Long story short, the practice became prevalent in the US and Canada around 1900 as a response to the rise of germaphobia. It was widely believed around that time that the penis, because of it's general function, was full of disease and the removal of any... extra folds, let's call them, would make them less 'dirty'. So, giving your baby a circumcision was the way to ensure they would be strong healthy men around the 1900s. And guess who was born around that time?
Strangely, it's never mentioned in the comics if young Mr. Howlett here was circumcised, but we can surmise that odds are he was. Coming from a well-off family that struggled with health, it's not a big stretch to think the Howlett's might have nipped the tip from their son. Therefore, statistically speaking, Wolverine's Lil'Berserker probably wasn't wearing any turtlenecks when he was a kid.
Here's where it gets fun.
So if we accept the fact that Wolverine was probably cut as a baby and that his healing factor doesn't regrow old wounds, then he must still be circumcised, right? Wrong!
Check out this scene from Wolverine's Civil War tie in:
Wolverine had all the flesh burned from his body, only to grow back moments later (A fact that's ridiculous, but is fodder for later articles) good as new. Back to factory condition, in most cases. See, I can make the argument that the healing factor would regrow as the aged man Wolverine is instead of a man-sized baby version of himself by virtue of some triggered blueprint in the man's brain. However, I would argue that any scars that he accumulated over the years would be wiped clean, including baby's first surgery.
Therefore, Wolverine is not circumcised because it grows back that way after severe crotch trauma.
And now you know.