ROFR stands for "Right of First Refusal" which is what Disney has on re-sales thru brokers. You make an offer on a re-sale, and Disney can buy it instead, its part of the contract when you bought the original DVC points.
Yes you can buy through Disney if or when (waitlist for them) points are availible. A resale agent often have the resort and amount of points you need.
Disney keeps an eye on $$ per point and enacts ROFR when price on a contract goes below a level they have determined or when they need to restock their offerings.
Although there have been exceptions (such as when they opened the new block of rooms at BWV last year), direct sales at sold out resorts are limited to current DVC owners.