I don't believe this rumor. Since July dates are current...they DO have more visas. Or else dates would not have been current...they will have to approve more people or move the dates back in the middle (less likely)
Visa numbers can retrogress in the middle of a month and become unavailable without prior notice. If there is a mid-month retrogression, USCIS could elect to stop accepting adjustment applications.
We are seeing decreased rate of approval already .. the guys who got approved today might have assigned the visa number earlier.....
Well if date retrogress now -- what will happen to guys who will file the 485 next month ?