The obvious change coming in the long run is that all existing resorts will expire and then be restarted and sold anew under the new resale restriction that will be applicable to Riviera. So beginning with the expiration of BWV, BRV, and BCV in January 2042 and ending with the expiration of CCV in January 2068, the existing resorts will be converted to the new system limiting any resale purchaser to reserving only home resort. For Disney, which believes WDW will still be around well into the 22d century, that is just a matter of time.
As to prohibiting resale purchasers of the existing resorts any further from reserving at the existing resorts, I have doubts another change is coming since the POS's of all those resorts provide that both purchasers from DVD and resale purchasers must be allowed, on the same basis, to reserve at both their home resort and any other existing DVC Resorts in the DVC system.
I do perceive more onerous availability problems at 7 months out developing in the next 15 years at the existing resorts. There will, by that time, be a large number of owners at those resorts who purchased resale after Jan 2019 and thus can only reserve at the original 14 DVC Resorts. And likely by that time there will be 4 to 6 new resorts (beginning with Riviera) where all the purchasers (total number potentially in the six figures) from DVD can also reserve any of the 14 original resorts. That combination will create significantly more demand at 7 months out than currently exists for the existing resorts.