A class 2 truck will always have a max GVWR of 10k. That is a government classification rating that has been around for decades and cannot be changed by a manufacture.
However, there is nothing in the rule books that says a manufacturer has to put a truck in a certain class based on the model number or name. Ford puts the F450 pickup in class 3 and an F350 in class 2 as an option. Then there was the fact that all 350/3500 SRW trucks prior to 2005 used to be class 2 trucks. Basically, just because it has a 2, 3, or 4 on the door does not mean it has to go in that class. It is just a name or designation given to a certain model.
What this means is that manufacturers are finally breaking the 2500s out of class 2 just like in 2005 with the 350/3500 trucks because the capabilities of these trucks far exceed the ratings of the the decades old classification system as I and many others have stated for a long time. This was bound to happen. The only bad thing for GM is that they should still offer a truck rated under 10k GVWR for those that don't want to pay additional registration fees and taxes. They probably do and just allow you to de-rate these trucks(numerically, not capability) as an option.
This is why a made a thread a few years ago saying we should get rid of terms like "half-ton" or "one-ton" because they no longer apply, and manufacturers will eventually surpass the outdated government class system. All of the 250/2500 past 2013 have ratings well over the 10k GVWR limitation of the class the manufacturers put them in so this is not too surprising.