No source beyond the 'leaked' presentation of questionable reliability. I don't see how this adds any value to previous discussions: https://news.ycombinator.com/item?id=7294762
Thus, your Bitcoin losses will be deductible forever until
you’ve used them all. This means that the $409.2 million
dollars is worth a potential $122.8 million dollars in tax
refunds.
That looks like value to me.I assume you did not read the article?
I am not a lawyer, accountant or American.