The due date for filing form 990-T for an IRA is April 15. Presumably, Schwab has filed for an extension of time to file. The extension form 8868 gives an automatic 6-month extension of time to file the 990-T.
So July 15 shouldn't really mean anything; the real filing deadline should be in October.
I suppose someone could override the form's automatic 6-month extension and only ask for a 3-month extension but that would be unusual. It would be gambling that all the information would be received in time.