In principle, the following applies to ALL signature cards (including follow-up cards!) from all signature card providers:
The "old" emails/documents were encrypted with your "old" public key and can therefore only be decrypted with your "old" private key (which is stored on your "old" signature card).
You will receive a new key pair with a follow-up card / new card. This new key pair cannot be used for your existing emails / encrypted documents.
It is therefore advisable not to dispose of the "old" signature card.
That a card has expired when decrypting DOCUMENTS with Sign Live! CC no influence. The signature card expiration date is displayed in Sign Live! CC checked only with the signature.