I'm sure there will be ownership beyond 2042 for those older resorts. But what we really don't know is when extensions may be offered and for what duration.
The 15-year period of the OKW extension was a bit risky for DVD given that it's such a short term. If only 40% of owners accepted the offer, DVD will receive 60% of the resort's points for a period of only 15 years. And I doubt they will be very successful in marketing 15-year contracts to buyers.
Of course, with OKW consisting of many stand-alone buildings, I suspect DVD will have some room to operate come 2042. It wouldn't surprise me if they found a way to keep certain buildings intact for those who own through 2057 while creating a separate condo association for other buildings or re-developing the property.
If BWV, BCV, etc. are to be extended, my current thinking is that we will see full 50-year extensions offered sometime in the next 10-20 years. They'll be discounted somewhat but still quite expensive.
Really I view that as a win/win proposition for
DVC. There are limited marketing costs involved (notices to the existing owners.) The price will certainly be higher than the present value of the extension years as was the case with OKW. Contracts that are not extended will revert back to DVC for full 50-year "new" sales in a few years, but the extension offer will help reduce the deluge of unsold inventory that would otherwise fall into their laps come February 2042.
Of course, offering extensions similar to OKW would help pad the sales numbers for a year or two. So from that perspective, it wouldn't surprise me if they announced extensions tomorrow. ;P