So, where did that (wrong) $23.8 million Barclays Center revenue estimate come from?

OK, I'm late to this wrongheaded 3/23/17 Newsday editorial analysis:

We do know that Barclays Center paid the Islanders $37.5 million in the year ending in June 2016. That payment made up the majority of the $58.2 million the arena spent on all fees, licensing deals and concessions agreements, according to the arena’s financial statements. But in the same documents, the arena estimated that by 2021, that total figure would fall to $23.8 million.
That leaves one more question: Is Barclays predicting a future without the Islanders?

Which Newsday clarified the next day:

The Barclays Center earned $58.2 million in aggregate revenue from licensing, concessions, sponsorships and other similar contracts in 2016, and estimated that revenue number at $23.8 million as of 2021. The payments the arena made or will make in the future to the Islanders are not included in that revenue data. A Point item on Thursday mischaracterized that data.

Where did that number come from? 

Well, it came from Barclays' 2015-16 annual revenue statement, excerpted below, which indeed estimated that "aggregate contractually obligated" fees would be $23.8 million in 2021.

But that didn't put the arena on some financial precipice. It just meant some contracts would expire and hadn't yet been renewed.

In the August 2016 Official Statement (prospectus) for the refinanced arena bonds, excerpted below, the arena management company projected a steadily increasing stream of income, assuming that sponsorships and suites would be renewed. That didn't mean an enormous cushion for debt service, but the refinancing of bonds sure helped.