Current share price indicates a market cap for the restructured company of roughly one billion dollar
With 5% of the restructured company to be owned by current shareholders the share price actually didn't fall by 50% rather than jumped by a whopping 1,000% on the restructuring news.
The current share price doesn't factor in that the shares might very well still end up being worthless - at first all stakeholders need to agree on the restructuring otherwise the company will file for a regular chapter 11.
I am not sure if the restructured company really deserves an enterprise value of around $1,500,000,000. While the debt comes down significantly and the interest burden also reduced the company still faces tough business conditions and an ongoing conflict of interest by its still largest holder Tariko. I would bet he is already working on ways to cheat the new shareholders again.