As far as DVC room requests go, these are my thoughts.
Before the change to doing all room assignments centrally, which was when TP were asked to send them in by email at 30 days prior (fall 2019 IIRC), each resort had it’s own team of room assigners.
DVC members were advised (by DVC) to submit room requests to Member Services so they could be added directly to the DVC reservation (which regular CMs didn’t have access to). And the official position of the DVC teams was to ignore faxes with room requests.
Whether they read them or not was down to individuals, and some teams were certainly reputed to ignore anything not on the actual reservation.
Now that everything is done centrally, there’s no need to go through Member Services. And anecdotally, DVC room requests through TP are more likely to be successful than previously.
But it’s only the TP community that really knows about the change, it wasn’t announced. For everyone else, who doesn’t use the TP room request tool, going through Member Services is still the only way for making room requests.
The really important thing is to NOT do anything at on-line check-in. And to make sure that any request to Member Services matches your TP request if you decide to do both.