Before you get too excited at the prospect that it could hint that a new iPad is coming, that seems to be highly unlikely. The new iPad Pro was only revealed a few months ago, so it is doubtful that Apple actually has a new model in the works. It is possible that this could be due to some production issues that has caused the delay, but we can’t say that with certainty.
Either way, what we do know is that the tablet is currently sold out for the 12.9-inch model and you’ll have to wait until July to get it. This represents about a month of waiting which is a bit unfortunate, but if you absolutely have to have it now, the folks at Cult of Mac have called around and found that some physical Apple Stores do have them in stock, so you can try calling your local Apple Store and try your luck there.