My understanding is that HP will not gauarantee the performance of the cartridge or the ink passed a certain date as their warranty documentation seems to indicate that it will work passed the expiry date.
That makes sense, and would be the same as ink for 4000. It continues to work past the expiration date.
But since all of these cartridges include electronic gadgets to read them, as well as the expiration dates, I decided to ask.
Better to ask a dumb question than to not know at all!