I don't think these historical trends are similar at all, and I don't believe that in 4-5 years Riviera will be anywhere near where it is now, once it's in the same stage in the "life cycle".
Source:
https://dvcfieldguide.com/historical-resale-pricing
With
DVC, there will always eventually be "huge losses" because the contract is guaranteed to be worthless a few decades down the road. So if a buyer buys with the idea that they (or their kid or grandkids) will hold the contract for 50 years, they really shouldn't care about the resale restrictions at all. But many buyers may initially buy with that intent only to have age, a geographic move, loss of job, divorce, death in the family, grown kids or other life issues come in the way. If/when that happens, those owners will eventually have to deal with the reality that their soon-to-be resale contracts are much less desirable by many (not all) potential buyers - it's just a fact. The flexibility of the "exchange" feature of a timeshare is too valuable to not matter much. That has to impact resale values, and it may do so by a lot.
Resale restrictions are not new, so you can take a look at other timeshare systems to see their impact over time. The Westin/Sheraton system (now part of Marriott Vacation Club) is very different but initially it had a handful of unrestricted resorts and then instituted resale restrictions for subsequent resorts. The unrestricted resorts in that system are truly unrestricted in the sense that resale deeds could exchange even into the 10-15 newer resorts that came after them. For many years, those unrestricted resorts sold for substantially more than restricted resorts on the resale market - and I mean like 5x more (although now everything there is hitting rock bottom due to skyrocketing dues). I don't think you'll see the same disparities at DVC, but there will probably be substantial price differences.