DVC salespeople are generally pretty good, but when the topic of resale comes up, they become your standard timeshare salesperson it seems. I wouldn't put any stock in what the salesperson said. If and when new resale restrictions are adopted, I'm sure DVC will either do it without notice, or will provide some official notice.
As other posters have commented, I don't understand why DVC would be bothered by resales. They have the opportunity to sell 100% of the resorts...no one else can sell the points in the first instance. And a vibrant resale market ensures there are no unhappy DVC members - if you don't want your DVC, you can sell it, probably without losing any money!
The only restriction on resale that I believe would make any sense is prohibiting resales while a property was still being actively sold by Disney. Resales while a property was being sold might well undermine Disney a bit. But afterwards, no. I use an analogy of a condo apartment building...why on earth should the developer care if the original owners sell their condos after several years?? Why would original owners be enthusiastic about buying in if they see that the developer is keen at undermining their ability to resell!
If Disney doesn't like resales, then fine, agree to buy back all contracts at a fair price and resell them themselves!