the SEC requires timely informing of material events...but no one EVER got in trouble for withholding good info....only bad info. there can be multitudes of business reasons to easily justify for w/h good info, but NEVER for bad info.
So in a nutshell, Koos can release the good news whenever it makes sense for him to do so...if we were rejected, he could not sit on that.
Either way though, the FDA never releases any info until the applicant does so first to avoid stock manipulations and ill-timed stock gaming.