If you have the talent Solinski has it doesn't matter what you did in high school. So he ran 90 miles a week and 8:45. Doesn't seem to have hurt him.
Coaches who look to those who ran a lot and didn't improve are barking up the wrong tree. There are those who may not have been born with the gift Solinski did and did big mileage and level off after high school. Those kids wouldn't have been near a top D1 program as a recruit if they hadn't rolled the dice in high school. The training they did didn't kill them, they just reached the limits of their potential sooner.
Bob Kennedy who ran 35 miles a week in high school, won Footlocker, and ran 4:04 could have probably broke Nelson's 2 mile record if he had amped it up a little sooner. Big deal compared to what he went on to do. Didn't matter, as long as he kept progressing that wouldn't have made a difference to where he ended up. Some people are just damn good.
However, in the larger scheme of things, the more young people we have training harder will raise the standards and more kids will have an easier time adapting in college and some will level off, others will go on, but the end result will be that the bar will be raised, runners will have to hit high standards sooner.
There is a fear that heavy training during the teenage years can hurt a career and prevent any runner from reaching their top potential but I have never heard a real physiologically based argument to how this occurs.