Frankly, I’m not satisfied Subaru has ever resolved the head gasket issue completely on the 4 cylinder motors. They just don’t seem to have problems with the 6 cylinders.
We get questions about head gasket issues with late ('07 and up) Subaru 4 cylinders even though Subaru claims the problems were limited to early '00’s models.
Perhaps the 4 cylinders are just too stressed and prone to overheating and head gasket issues regardless of the year made. If I was to ever buy a Subaru I’d buy a 6 cylinder and enjoy the extra power and live with a bit less mpg.