I think you're right about the potential for the third-party hotels, but it's also been reported quite a bit for the last month+ that the attraction of Disney is the control they have over the hotels and surrounding property. Would those third-party sites be willing to close their hotels completely to outside guests? Maybe, but it's also harder for them to move guests than it is for Disney to do so.
I have not bought in to the "players won't stay at anything less than what they're used to" narrative. A good chunk of these players lived in college dorms a couple years ago, so it's not like they're so removed from lesser accommodations. The reality though is that the players understand that sacrifices have to be made to complete the season, and they have millions in salary depending on resuming the season (not just this year - the more money the league can make now, the less the salary cap will go down which is going to drastically affect their future contracts as well, for multiple reasons). Plus for many of the highest paid players who might be sacrificing the most in what they're used to - they are the players who have the most riding on their career legacies with the outcome of the season (LeBron doesn't have much time left to win any more titles, etc.).
For the list with "distant" DVC, I just don't know that they could reasonably keep guests separated well enough. Grand Floridian the DVC guests have no dining except in the main building, I believe. Same thing with Contemporary and Polynesian (I guess you could consider the Oasis pool bar). Poly also has guest check-in in the main building. Also, how do you manage with the monorail stopping there?
Yacht Club has a bit more in amenities without Beach, but the pool might be an issue and they are just on top of each other. Caribbean is the most separated, but assuming the Skyliner's running, you have the same problem of how "sealing" off the resort area from others, although not nearly as much as with the monorail resorts.
Port Orleans would certainly make sense as far as location goes and it is a bit better than the values. Pop and AOA could work I guess and just not run that line of the Skyliner. Notwithstanding my statements on players being able to handle the accommodations, I still have a hard time seeing them put in the All Stars. Although, that could certainly be an added wrinkle to the idea of letting the higher seeds pick - let them also pick at which resorts the others stay. "Oh, and for this team we don't like, you get All Star Sports. Two to a room too!! Mwah-haha!!"