The loss of a sportsman's life is always tragic and although not a drag racing fan by any stretch of the imagination, I am saddened to learn the news.
Maybe top flight classes have run their course at least for 0-400 metre distances. The number "300" always seemed important for the fan base, but at some stage the "cars" will reach that speed even at shortened distances -- that's the point of the race, after all, to go as fast as possible... I really can't think of a way out of this other than weighing down and slowing down the cars, but then again, how interesting is a contest lasting a few seconds with the winner and loser within thousandths of a second of one another going to be for the next ten years? I don't know. The sanctioning body is apparently walking the tightrope between a "spec" series at 300 mph and differences of 0.xxx seconds on the one hand, and space travel vehicles on the other. I don't envy their task.
I'd like to see a meaningful measure of true road car acceleration from a standstill, incidentally. 0-1000 m (two and one-half drag race courses) to allow everybody to fill all gears till redline, and see what numbers come up. Magazines used to test this, and it was very telling, but I've not seen it done in years.