It’s possible that with the passage of time (give it a few more years) the number of head gasket complaints on newer Subarus may increase.
I do respectfully disagree with Caddyman that Subarus are total junk. However, I also think they’re vastly overrated and that any sales increases are not due to the reliability factor. It’s due to perception of reliability and perception is what sells cars.
In this particular case it seems to me the car is not at fault. It’s the owner of the car who is at fault for not being aware of an overheated car. A car does not overheat and cause engine damage instantly. It takes a while and somewhere during all of this a temperature gauge was ignored.
With overheating bad enough to cause head gasket problems having some piston ring and/or valve seal damage is at the very least probable.
If the car were mine I’d run a compression test on all cylinders. Any cylinder with a head gasket breach would be irrelevant but if the test shows ring problems on the others then one would know for a fact the engine is not worth doing the gaskets on.