I'll be 74 in 2042. In addition I have Poly points that'll be around until I'm almost 100.
Whether an expiring resort is a good deal for me after 2042 depends on the deal. IF
DVC retains its value, IF there is some extension offered that would allow me to continue to preserve resale value, then whether I would buy in or not has more to do with the financial considerations than future use of myself or my heirs.
Lots of IFs.
But. Even if I were a young owner, 2042 resorts at WDW will almost certainly be around and current owners will almost certainly have a chance to continue ownership at a substantial discount over new points. Whether that makes sense for then older current owners depends on the deal.
I wouldn't let 2042 scare me off buying a 2042 resort. I didn't let it.