When you're denied, you are also notified that you'll have to close your RDSP. You then have one year in which to get a doctor or a nurse practitioner to fill out a form that says, “I'm pretty sure this person can be re-eligible within a year. Please hold.” They'll hold for one year and then after that, if you haven't become re-eligible, then it's gone. We're in a really tight window for some folks who got notified six months ago that they are no longer eligible.
On November 7th, 2017. See this statement in context.