What's with all the comments on that Apple thread where people are saying "I didn't have a grain of cereal, rice, etc between the screen"? Are Macbook screens that fragile now?
Yes. The tolerances between the top case and the display are that tight when closed. Apple has a literal support page telling you not to close the laptop lid with anything thicker than 0.1mm.
Many laptop screens are that fragile. We repair computers and it’s quite common to see a broken screen because someone closed something inside the clamshell accidentally. I’ve seen everything from pencils, pens, erasers, paper with staples, paper clips…
Some models have little to no clearance and if you close the lid with a grain of rice and apply pressure it'll break the screen. Closing the lid probably isn't enough, but picking it up could be.