How would that work when the brain is rotted and they would just be a clone of the person?

This is probably a much more short-term thing.

They're gonna try to regenerate the nervous tissue of patients who have suffered a traumatic brain injury. Those people are brain dead and kept alive through life-support. It's not like they gonna dig up corpses, so yeah, I don't know what's so bad about it. Neuroregeneration is already done in othe parts of the nervous system. 

That article is misleading. The type of people who meet the criteria of the study are people with traumatic brain injury. These patients are typically kept alive on tracheostomies, mechanical ventilators, and gastrostomy tube feedings. They have pulses and working organs but have no neurological and/or neuromuscular activity. They're not dead, at least in a cardiopulmonary sense. But, they're prone to infections due to skin breakdown or pneumonia.

Families whose members suffer traumatic brain injury or brain death have been hoping for this kind of research forever. Some of those who end up being vented were at one point completely independent with almost no comorbidities. Imagine having to take care of a son or daughter kept alive only by a machine that breathes for him or her.