Not sure what you mean by the 60 day "thingie"
As long as you cancel a reservation at least 31 days in advance, the points are returned to your account with the same status they had before you made the reservation. If there is availability for your June dates, MS could just cancel the August reservation and reuse the points for your June reservation. No problem. Don't know what the availability will be - good luck on Monday when you call.
If you made the June reservation and then had to cancel that, your points would be in holding status. That means the points couldn't be banked, expire at the end of your current use year and cannot be used to make a reservation that will occur more than 60 days in the future.
The 60 day rules says that you can't make a reservation for a
non-
DVC resort in the last 60 days of your use year if your stay will also occur during the last 60 days of your use year. So for example, if you have an August use year and wanted to make the June reservation at the Poly, you'd have to call to do it before June1.
HTH.
God Bless your DH and your family and all of the military families who support them.