Can a blender be used to make emulsified sausage?
I think your issue, using a high powered blender, is that the friction in such a blender produces quite a bit of heat. You will need to account for that.  Secondly, your grind might be too thick for the blender to circulate effectively.  You want your meat near freezing for the initial grind, so you will want to pre-grind for sure.   However, then, some heat helps with the emulsion.  I could see it working, with some pulsing, then maybe some time in the refrigerator, then a return to pulsing.  It depends on your blender, the amount of mix, and your patience.  It could work.  This might help you consider the variables. 

Upon further investigation, heat might not be your biggest issue if you choose to use a blender.  In the case of emulsified sausage, "emulsification" is a bit of a misnomer. A blender, however, could cause a problem by over-processing the fat particles, leading to a less stable "emulsion."  According to the source I just linked:


  Fat emulsification involves, as mentioned previously, the reduction of fat to a small enough size that the extracted protein can coat or entrap the fat. Of the fat particles are too large we will not get a smooth, stable emulsion but if the fat is chopped too much the surface area may be too large or too many fat cells may be broken to yield a stable product.


Again, you might be able to make this work with care and patience, but a high speed blender is probably not the best tool for the job.