You're chances are good, very good -- in the sense they have always offered free dining in September, ever since starting the dining plan.
But, I would say there is absolutely no guarantee. While currently offering September free dining as a bounce back offer, and as an offer to international guests, they specifcally excluded it from being a general public American offer. And they have already signficantly cut back other discounts -- October is a pretty slow month. While they are offering free dining for some select October dates, there is absolutely nothing for the general public covering much of the month, no room discounts.
So if I was a betting man, I would bet we will see free dining next September, or some variation of it. But it's not as safe a bet as it used to be.