I had a couple theories I wanted to share, as well as some info I gathered after thinking about these theories.
First, in regards to the picture stating 12/08: I have a feeling this is from an authorized retailer, which would only indicate that THEY would be launching on 12/08, leaving the 11/21 still an option for w/o or corporate stores. The reason for this is the wording on the red dinc2. They mention that the units would be shipped direct from HTC and not "our VZW DC". This struck me as odd, as why would a corporate office have to refer to themselves as "our VZW DC"? It would make more sense if that was coming from an authorized retailer instead, especially as many of them cover multiple carriers. Even if I'm wrong here, there's also the possibility that this is merely the in-store date, as the prior info we had said 11/21 but web only.
My second theory is in regards to VZW's exclusivity: I doubt that when Samsung agreed to the exclusivity, that they extended it from the date in which VZW decides to release the phone, but more likely from the date in which they (Samsung) were ready to release (say 11/17, when UK was ready). If they extended it from the date VZW decided to release, then Sammy'd be in an awkward position if VZW decided to drag their heels. Now Sammy could potentially lose $ when releasing to other carriers if VZW decided to wait until just before another carrier is about to drop a similar and/or better phone. I doubt they would have overlooked that possibility. If the agreement was from the date in which Sammy had the phone ready, then VZW would want to get it out soon to maintain some amount of exclusivity. Otherwise they could wait too long then only have it exclusive for a short period of time, hurting their sales.
Based on this, I decided to try calling a local store, and hoping to catch them off guard I asked if they had any in stock, rather than if they knew the release date. The woman I spoke to said "that device hasn't launched yet, but is expected to next week." When I pressed further, she backtracked and said they didn't have a release date yet. You could take that as her initially thinking of the 11/21 date, then realizing that it's been pushed to 12/08, or you could take it as next week being correct and her trying to deflect the fact that she gave me info she wasn't supposed to. I'm hoping for the latter, but I guess we'll see soon.