|Photo via Yahoo! Sports|
I suppose that may be because they wanted to keep the "midnight" logo (i.e., the one with the black skyline) in circulation for whatever reason, but I have another theory. It's no secret that a) the plan was for the black alts to see very limited use in 2012, and b) the rest of the plan is to phase them out entirely in favor of a blue alt in 2013. So what do you do if you're Majestic and the MLB fan shop, with a storage room full of authentic black jerseys that will be obsolete in 6 months? Slap another patch on them and get them sold before then.
Surely, the tops the team was wearing weren't leftovers from 2011, but my hypothesis says if you buy an authentic for yourself, there's a good chance it is. Think about it. It just so happens that the black alts are the only style that didn't change for 2012, and they're also the only ones with the dual patches. Obviously, just adding an anniversary patch is much easier and cheaper than replacing the old one.