I suppose this one will also won't be user-rechargeable? Will the unit need to be returned to the factory for battery replacement if it's ever deployed?
PLBs currently are prohibited from having rechargeable batteries.
The PLB would need to go to a service center for battery replacement. If used for a real survival situation, the manufacturer almost always simply replaces the unit as a courtesy or services it for you.
As for end of service life issues, in 5-6 years the new PLBs available will be smaller and cheaper and nobody expects to be replacing batteries. PLBs have become disposable, effectively.