TUG does not have access to what's available at RCI or II directly but many times you can get info as to what other people are pulling online using their strong trading weeks. If someone posts that they saw so in so, just call RCI immediately and request it, they may or may not give it to you. Both exchange companies stratify owners. That means that if they rank resorts based on various factors and end up with a score of 10-100, they may only let owners have a unit that ranks between 90-100 if their deposit also ranks in that range. Much like Seniors don't go out with freshman.
I'm curious as to what your friends deposited, how far in advance of their week was it given to RCI and how far out they were looking. Since there are several units there that bulk space bank around a year out, I would have to assume that your friends do not have enough trading power and/or were not looking a full year out. And before you ask, NO RCI or II will not usually tell you that you have no chance. Bulk Spacebanking means that the resort gives the exchange company a chunk of units periodically rather than depositing when the owners tell them to. That makes it pretty easy to get certain resorts at certain times.
Remember that the units sitting in the bank at RCI and II are, at least in theory, the units that no one had an exchange request for OR did not have enough trade power to grab. So the idea is to start an ongoing search as broad as possible as early as possible. With RCI, it can also help to search online as they seem to let more of their top units through to the online database than II. As for searching what's online with II at any time, I'd be happy to check myself from time to time to help a fellow
DVC member look for ideas.
As Doc noted, make sure they are depositing a full year ahead of their week and searching at least a year (better 2) ahead of when they want to travel. I would suspect that if they are going to get anything now, it will be in the 30-90 days timeframe before their travel. Good luck and I hope that at least partly answers your questions.