The mobo makers simply test w/ whatever they have available, they should have a set of those, but may have been testing them on another rig, or just didn't have time, there's way to much DRAM out there to test all the available sets on any one given model of mobo
Those will be fine, and still a little faster overall than the 2133/11 set listed. Snipers also OC well, so could look at running them at 2133/10 or so
The mobo makers simply test w/ whatever they have available, they should have a set of those, but may have been testing them on another rig, or just didn't have time, there's way to much DRAM out there to test all the available sets on any one given model of mobo