i think the valve body issues occur from dirty fluid causing wear in the lock up solenoid which then fails over time. Been through it myself. The clutch in that circuit does wear so when you disassemble the valve body, you can see the metallic film in the passages of that circuit. Can possibly be prevented with fluid maintenance. As talked about on here, possible the easiest way to do that is to freshen the fluid every 35,000 miles give or take by dumping what is in the pan. You'll get about 1/2 of the fluid out and not have to do a complete flush which is sort of a pain. Repeat at intervals.
Subaru has continually done minor things to update over the years. The biggest one, which I don't feel is a good update, is adding the fake shifts starting in 2018. New potential buyers complained about the CVT feel that were used to regular style transmissions so Subaru added fake shift points to make the CVT feel as though it was shifting gears. To me this is truly dumb. Partially defeats the whole purpose of a CVT and also places more stress on the belt with the extra jerking between shifts. Seems to be robust enough to handle it though. I would not hesitate to buy a new Subaru because of it. If you plan to keep it long term, do some sort of fluid maint and you should be good to go.
