No, not entirely... If there's a backlog of comic packs not moving at all, and easily discernable pegwarmers, and repacking the same things that aren't selling, that's a distribution issue.
Unfortunately what happened as near as I can tell is things backed up because sales slowed down on them. Some of it is because they were lame choices (again Jeff's Marvel example, which backed up here a lot and took a while to sell through, and even saw dumping at discounters), some I'm sure is economic issues (something has to go, for many people, and comic packs are a secondary line like Deluxe and whatnot... That's probably what went then, due to its higher pricetag), and you add another steep price increase on these ($9.99 to $12.99 isn't a short jump) and there's a mix of reasons. I'd also say some distribution issues probably didn't help, but they just don't seem to me to have been a huge impact as these other issues were.
Now what has happened is retailers sales data shows the line slowed down, so they order less whether there's space for more or not. They fear their ability to sell-through at a rate they want, and so they'll only order a case at a time... That's not distribution, that's simply retail saying these don't sell fast like they used to.
The thing that doesn't imply distribution issues (I'm sure there were some things that should've been packed less or more) to me, is that there really weren't many sets one could cite as constantly repacked, constantly clogging up the system... It's not like Yarna, or LEgends Plo Koon... The only set I see routinely is the Shadows of the Empire one, and that really isn't preventing stuff from getting to the pegs... Retailers refusing to order more, for one reason or another, is. They just don't want a massive glut of sets out there right now it seems, and at this time of year usually they're anxious to have the pegs filled. I think they just don't have faith the line is selling well anymore.
I think if the comic packs continue, you'll see less pegspace devoted to them... That's how they'll be limited by retail. I think Hasbro, if they continue them, will look at simply doing fewer sets in a year... Similar to what Legacy may be seeing in 2010 as well. Some waves will get cancelled, things will shift around, and so on.