This sounds like the phenomenon where any tiny unrelated issue with a plane is scrutinized by the media after an accident, even if these minor issues are common. I have no idea if this issue is serious, but I wouldn’t assume it is until we get more info.
A crack formed on the outermost of 4 layers. It’s within spec but should’ve been caught on inspection. This is a bad look for ANA’s inspection team (which might be Boeing? I’m not sure), but not a manufacturing defect afaik.
I’m tempted to lock this for sensationalism. The top of four layers of cockpit glass cracked. While it’s SOP to return to port after detecting a crack in the cockpit, this type of damage isn’t uncommon in Boeing aircraft, including the 787:
I mean, it’s not great to have planes be forced to turn around because of cracked glass and I think this is the first 737 to experience the issue, but it’s not a big deal imo.
Stress is eventually going to cause wear and then failure to lots of parts, especially ones on the outermost layer of the plane. That’s why they’re over-engineered. Does there need to be 4 layers of cockpit windshield? Probably not, but humans make mistakes and we’re lucky to have those extra layers so we can turn around and land safely.