From the glow of the red emanating from the kiln, it looks to me that they're running these at pretty high temps. Do you think the elements might be corroding now?
I think elements are always in the process of oxidizing. If they run these at a high setting they will likely fail earlier than elements in a system designed for pizza, but they may have a good service life- I couldn't say.
There are coatings that you can put in a kiln that help reflect heat and resist corrosive atmospheres, and coatings for elements that will help them resist corrosion. Some fairly respected people make amazing claims about "ITC 100" and "ITC 213" slashing their electric bills and saving element life.