Thats extremely unlikely. Maybe it could theoretically rent for that it wasnt regulated, but it obviously is, so the actual rent he could collect on the unit is a fraction of that.

Its sealed up because the cost to renovate the unit is likely so much higher than the rent he could legally charge that he would never recoup the cost.

and having someone in the unit that may not even be legally habitable, or just barely habitable, to collect bread crumbs and field 20x service calls a week is not worth the hassle.

He likely bought it with an understanding that the laws likely will change at some point. But he could also be wrong and they might not change, or at least not in a time frame he can take advantage of.