Actually I think that's intentional because of the home resort advantage. It makes it even more obvious. And starts you thinking, I need to buy more points.
Seriously, DVC might not allow it because every time you select a villa, it pulls that room from the availability list. And then when you close without making the reservation the room goes back into the availability list. But for a while the room isn't available for anyone other than you to book it. So the only way you can see if a room is available is by being eligible to reserve the room. Therefore you have to wait until you are eligible to make a reservation at the 7 month mark.