Hate to say it but there doesn't seem to be any agreement as to what causes the failure, some standard well maintained cars go bang, some treated like crap don't.
Alot of whats said in the vid is just good practise for any turbo charged car and especially impreza so is solid advice, but wont change anything as far as ring land failure or HG failure goes. Only true fix is replace pistons, head studs and gaskets.
I suspect the only reason there seems to be less failure on later ones is cos there's less of them about, clinic's already had 3 2014/2015's in that have failed due to ring land so its still there as an issue and IM (subaru UK) still won admit there is any issue, despite loads of cars out there having a and in some cases several new engines within the warrenty period.
Oil change period gets talked about alot, how its driven makes a big difference to when, 5k for a normaly driven car or 3k for a weekend toy is prob about the right sort of level, weekend toys tend to be driven harder than daily drivers.