unless things have changed in the the past few years, it is not a req for the company to issue a pr for a conf call. only req i'm aware of is that companies have to report their results within 45 days of the end of the quarter (unless they file an extension request with the sec).
many tiny companies don't even have calls, they just put out a release with their numbers.
imo, if they're not ready with data by 8/15, they'll probably blast out a pr with Q2 earnings and then have a call to discuss it a few days later with data findings.