The second, third, and fourth sentences seem to imply otherwise?
>The test is meant to push the plane beyond its limits. Engineers had the plane pressurized and on the ground. They loaded it up well beyond capacity and bent its wings in an extreme manner, in a way almost certain to never happen in the real world.
and also further down, more "not necessarily a normal test" evidence:
>... The ultimate load test is the latest in a series of tests that Boeing has been conducting on this full-scale test airplane over the past several months."
During the ultimate load test, the wings are then pulled upward. To pass the test and be certified, the wings must bend without breaking until the load on them reaches at least 150 percent of the normally expected load.
…
Sometimes this final test is continued beyond the 150 percent load target until a wing actually breaks. But not always.
…
This time, however, though the wings did not give way; it was one of the doors that failed — an outcome that is definitely not supposed to happen.
The cargo hatch blew open and the cabin floor collapsed on account of differential pressure, disabling the rudder, elevator and rear engine controls.
This may well not happen on a 777X -- various other airplanes have lost part of their cabin structure without crashing -- but an unexpected event calls into doubt your design.
It's literally the first sentence of the article.
I doubt Boeing were pushing the envelopes further than the FAA required. And a door fell out.