If this reduced trade in value model is the new way Samsung are going, they are really going to struggle moving the Fold 5. I can’t see many people paying retail value for a $1700 phone.
Depending on the market/country, Samsung did provide a certain "guarantee" of certain amount of trade-in value in last-year's promos of the Fold 4, if I remembered correctly (or was it the Fold 3?). Let's see how that turns out.
Also, trade-in values are not really based on the original price of the traded in product, it is based on the demand of such product in the secondary market. If there are not that many demand, then the trade in value can be quite poor. In my country, sometimes cheap Xiaomi phones can seemingly have better trade-in values (as a percentage of their purchase prices) compared to more expensive phones, simply due to the higher demand in the secondary markets.
Even Apple is reducing theirs, so this is not a Samsung exclusive thing. We are at peak smartphone, where smartphone shipment are declining, people are keeping their phones longer, markets are getting saturated, and the economic downturn is not helping. People who want to keep their lifestyle of upgrading their phones yearly just have to adapt accordingly.