So I got my email from DRI today re the Destination Exchange roll-out. Here's some of my take, which is a continuation of things I have been posting for ten or more years.
Like any decently run company, travel and hospitality companies, including but not limited to timeshare/vacation companies, are looking to expand the amount of business they do with their customers/clients/saps/obligates. A basic strategy is to siphon money that your customers are spending elsewhere and bring it into your sphere. This is known as "extending" your services. It's like ordering something on Amazon or buying alcohol at Costco or Trader Joes. While you're there you may as well fill your cart with other things that you would like, and save time (and perhaps money). I don't have any problem with DRI doing so; in fact I would be worried if they didn't do so because that would mean was involved with any ineptly managed company.
When we joined the Club, I considered the business model - how DRI was identifying an opportunity to capture for themselves money that members would otherwise be sending to an exchange company. And making sure that model worked for us. So, one thing was exchange company membership fees. Since II Gold membership was included in Club dues, that was money had been sending to an exchange company that now went to DRI. A second thing was that by using the Club we could book units throughout the system without paying exchange fees and we could book directly if space was available instead of having to put in an exchange request. And if we still wanted to make an exchange, we could do so through II, and we knew exactly how many DRI points would be required for the exchange. And we didn't have to worry about trade power since DRI points could grab anything in inventory (or on a pending exchange). Since the Club covered many areas we wanted to travel that was a good trade
In that vein, my take on this is that Destination Exchange is just a way for DRI to retain in-house money that DRI members are spending with II. If a member completes an exchange using DX instead of II, that is money that flows to DRI instead of II. The backside question would be whether DRI creating DX causes II to downgrade the trading power given to DRI exchanges in II?