https://jalopnik.com/chevy-silverado-gmc-sierra-pickup-truck-stop-sale-roof-1851110020

sample quote

In a statement that GM supplied to Motor1, GM confirmed that the trucks were built with the split roof panel. It is concerning that these trucks which are marketed as tough and durable, and yet potentially left the factory with cracked metal roofs bringing all quality control measures into question

end quote

It’s not a Bug, it’s a new feature.

GM has always used its customer base for QC.

Hm. Kind of odd since a body-on frame pickup shouldn't have any real significant stresses in those areas.

Looks like it is cracking on the sharp bend

I went to the link the OP provided, which contains another link to the official NHTSA report. The service procedure page for the PASSENGER side roof panel joint repair shows a diagram of the DRIVER side.
Our government in action! You can't make this stuff up...

It's GM. GM is and never has been noted for their quality of product. They rely 100% on touting themselves as "American" while they sell junk.

It's a time-release sunroof they've been working on...

I agree with this 100%, as far back as I can remember, early 265 Chevys had issues, no oil filter, in 58 the turboglides? were pretty iffy, early corvairs weren't too well thought out, moving into the Vega era, early ones were dumped on the public, bad motors weren't uncommon at all, some had rear end troubles, I liked them, but they were for the most part throw away cars, not worth the expense or time to repair.

Then there is the 350 diesel saga.

And the cadillac 4.1 engines ..

modern stuff? I am not to well versed on that, although there are plenty of bad cam/lifter Chevys running around, neighbor just got done fixing his 2017, did the work himself and still spent a couple thou I think he said, eliminated the v8 6 4

In all of this, GM has managed to build some pretty damn good pickups over the years, up until around 2007 in my opinion.

Since GM seems to be the subject of this thread.... 47 percent of Buick dealers are telling GM to put their electrisical vehicles where the sun don't shine.

link -> Nearly Half Of Buick Dealers Take Buyout Instead Of Selling EV's.

didn't GM ever hear of "Ram Tough" ?

GM has saved over $9,000,000 annually by eliminating a good bit of welding on all their vehicles. They switched to a structural adhesive for joining key body panels. I am wondering of there was a modification to the formula that railes or if the "incorrect amount" was applied tha is causing the failure.

i have very little experience with that adhesive, but with what little i do have, when it's applied properly, a guy won't get the joined panels apart with a bazooka !
you have a valid point about the adhesive, though.

Ford & Chrysler have used structural adhesives for a long time, as have European carmakers.
And yeah, you generally have to cut around or through the stuff.
Applied correctly, that and literally 4 good spot welds are holding a lot of pickup bed sides on.
Also works great for deleting moldings and nameplates, and pie cuts on stretched wheel opening flanges.