I suspect based off speaking with a Glock Factory tech and the evidence that is out there, however sporadic that Glock went with the no reload/lead bullets for the liability factor out there, particularly with their early Generation 1, and 2 Pistols. (Also the unsupported chambers, remember those? Hence why lots of us have a bulge remover for our reloading kits) I think that there was instances of pistols blowing up early on due to the perfect storm of lead hardness, powder, velocity, cleaning and the barrels that came off the assembly line that day. That being said talking with one of their factory techs again, stating that jacked loads are fine so long as they are in spec, but any lead munitions, Factory or otherwise are not to be used in a glock barrel. Is it overkill? Yep. Is it probably CYA? Yep, but I also did several years as an Armorer/Direct Support Repairman for the Army. There are things that I was saying or advising that I would contend with, however there also was significant issues or things I mentioned that were indeed a concern and there was reasons why you did something in a specific way, or not do in a specific way.
Me? I dropped the hundred bucks on an aftermarket barrel. I considered it cheap insurance for lead usage, vs the cost of a 500 pistol, plus the use of my right hand, arm, left hand, arm, and eyes/ears/face.
Again, this could be a matter of some barrels exhibit leading to dangerously unsafe levels. It may not be all of them, or only due to a particular set of circumstances. Shoot Lead or any reloads at your own risk. While there is a lot of "google" reports out there and google information sages I have seen what others have in accurate reports. Some barrels will lead unusually and in a potentially dangerous way. It may not be your barrel. Do what you feel comfortable with, but its you that has to live with it if something goes wrong. Like it is with anything else out there.