Well, if that happened, and there was nothing else in the subclass that would cause me to override these methods, then I would do what you've suggested. However, that's a pretty unlikely scenario and I don't see any reason to add the extra complexity until it's actually needed. My opinion is that the code should stay as simple as possible until the requirements demand it be more complex.

I've also seen this sort of technique used for runtime configuration (e.g. use Storable or Data::Dumper for serialization), but that doesn't seem to be called for here.