Last March, with the then "new" system, I had no problem at all in switching a resv at 7 mos from SSR to BLT. It couldn't have been easier or quicker. All MS had to do was switch the resort on THAT resv & then get the extra points from our acct.
Well, I did the exact same thing about 10 days ago, and guess what? Under the current "new" system, a modification of the resort could not be done. I was told that the old one had to be cancelled, and a new resv made. I told her how it was handled a year ago, but she (MS) insisted that it could no longer be done that way. It took quite a bit longer this time. It worked so well last year!
Luckily, we're going in Sept when it's much slower, and I wasn't worried about losing a room. However, if we were looking at a hard to get resv, then that would have been a different story. It's too bad that
DVC / Disney had to take a step backwards in this process.