Probably not.
If you are on a 7000 squawk, he may genuinely not know which "7000" (of many) is you.
He may have a reason for concern though, otherwise he would not ask. Maybe he has a "7000" close to CAS somewhere.
A smarter way would be to ask you to squawk ident. I am not sure however if that is ever used with a 7000 squawk.
If you were on an individual squawk then he would not be asking the Q. He might ask you to confirm your altitude....