I have never heard of this problem. Stamped drops on a fixed are not inherently dangerous. Take a look at the ends of most true track bikes. There is so much misinformation and BS coming from so many know-nothing-know-it-alls in the bicycle world. Its true in every area of life.

Think it through. It's an 1/8 inch thick piece of steel. Cars and bridges are made out of the same stuff. You are not tough enough to tear, rip, or break it. For the first 60-70 years of bicycle history stamped drop outs were about all there was. Many, many of those bikes supported fixed drive trains.

If there is a weak point, it is in the area where the stay and the drop meet. It won't matter if the drop is stamped or forged. But again, you are far more likely to damage the head tube or the seat cluster through fatigue or a crash. Don't worry about it.