Jesus you would have to be brave to assume much would survive, unless that frozen was in liquid Nitrogen.
It can be surprising how tough yeast can be, the oldest yeast that survived bottling that I can recall came from a shipwreck circa 1710 in the English Chanel, mind you we are talking very cold (<0oC) totally dark and no O2 ingress, some researcher managed to coax a cell or two back to life.
Modern "Dried Yeast" is freeze dried, if you don't freeze the yeast before drying as the water is evaporated out, the stuff dissolve in it (both inside and outside the cell) concentrates. In effect it gets more and more "salty" it will reach the point where it is starting to damage the cell and its internal structures, in similar way that needles of water ice forming can.
The whole point of adding Glycerine is to stop the formation of ice crystals and the harm they do.
I would also be very concerned that the yeast may not be the same after freezing, good way to cause mutations, the freezing process will also stress the hell out of the yeast.
As a home brewer who cant afford a $20-30K freeze dryer and who wants good healthy yeast I would look at Glycerine freezing, followed by a full lifecycle starter or two, to make sure the yeast was not only alive, had a high enough population and was at full vitality and hadn't mutated into something unexpected.
Mark
