Hello & Welcome to Just Answer,
I'm Greg and will do my best to assist with this issue today.
Sorry I didn't see your question earlier.
To answer your question directly:
It is very UNLIKELY that any entries in the current phone book can be "automatically" transferred from the OLD system to the newer generation of Panasonic phone systems.
This is because most of the current systems have a "shared" phone book, where ALL of the entries are actually stored in the memory of the MAIN BASE Unit of the newer systems. So if a phone number is stored by ANY handset of the newer systems, any handset registered to the newer base unit will have access to those stored numbers.
So if you do decide to get a newer system, I would recommend that you keep the older system long enough to "manually" copy the important numbers from the old to the new system.
I hope this helps answer your question.
Please let me know if you have any similar questions.
Cheers, Greg A.