Before they found this, they knew for certain that people were dead when they had no apparent brain activity. Now they've discovered this, they know that was wrong.
No. Nothing of the sort. This article has nothing to do with patients who have no brain activity or, in your words, 'had no apparent brain activity.' Nothing. Nada. Zilch. Zip.
Patients in a persistent vegetative state have brain activity; they're not declared brain-dead because they have brain activity. The patients in this study all had brain activity and were never declared brain-dead.
All of the patients were determined to be in a persistent vegetative state.
The study showed that some patients in a persistent vegetative state have some awareness of their surroundings but cannot respond. Although in a persistent vegetative state, some patients showed EEGs similar to a conscious person in response to a statement such as "there is sugar in the coffee." Some did not.
At the end of the day, all of the patients in a persistent vegetative state remained in a persistent vegetative state. None of them were brain-dead to begin with, and none of them were brain-dead at the end of the study.
Thank you for the correction. You are right.