Very highly unlikely. It is true that there are legal proceedings currently ongoing about unfair charges, but you are referring to something else entirely.
A contract is only legally enforceable if it has all the relevant information. Now, if there were any mistakes in contracts before 2007, the card issuers would have very quickly realised and sent out new cards attached to new terms and conditions, or sent additional terms and conditions to all its card holders.
There are some companies out there who are happy to charge a fee to tell you if your credit card contract is legal and enforceable.
Now, common sense tells me that the very first claim received by a bank would send alarm bells throughout the industry if there was chance of unenforceable contracts out there.
Those cards would very quickly be replaced if necessary.