The basis of sous vide is to cook the meat to the desired level of "doneness" (directly related to temperature of the inside of the steak) and then sear the outside. Searing the outside is mostly decoupled from the inside cooking because it happens fast and thus only on the very outside layer of the meat.

I mapped this strategy directly to eggs, but it probably would work poorly. With a steak, "sear the outside to your preference" is easy. With an egg, "cook the whites without overcooking the yoke" is likely to be difficult.

Your suggested method of using the bath to maintain the water temperature would probably work well and probably result in less "rubbery" whites, but probably is overkill compared to maintaining the water temperature at 212 degrees (trivial) and control cooking via time per the article (and tradition). Plus you would have to boil 3,000 eggs to scientifically establish the new cook times. ;-)