The NBA's massive TV deal was announced in late 2014, and was put in place for the 2016-17 season. So, starting from around 2015, there was no realistic scenario where the league's salary cap would go down. Plus, by October, the league probably has a pretty good read on its revenues for the upcoming season, which is what sets the salary cap for the following one. Season ticket sales are locked in, overall ticket sales are probably known with reasonable certainty, local TV contracts are in place, and the retail outlets have already stocked up on the merchandise for the Christmas holiday season. Even a 2007 recession were to hit, there would be a lag before it affected league revenues, and even in that case, the cap gurus would simply redo their projections at that time. No real need to model something that is not even forecast.
So, I could believe this anonymous capologist never had to forecast a down year. Most probably came in after the recession (I get the feeling that turnover in those positions is fairly high).
It still seems unlikely. Silver is either on his way to Shanghai for his pre-planned visit or is already there. There is a lot at stake for both sides financially to work something out. While indeed a distinct possibility, China hasn't yet cancelled the NBA's TV contract with its Chinese broadcast partners. But I also would believe owners' wanting to fully understand the implications of a revenue drop in the event it does happen, as the probability is no longer zero.