If I am given a final K1 as a beneficiary of an estate from the CPA doing the taxes, does that mean the estate has been closed?

Ask the executor or the estate.  Estates can issue some distributions long before the estate has been closed or a final estate tax return is filed.

Thanks.

It depends - a final K-1 would mean either the estate was closed and a final estate return was filed during the current calendar tax year or you are no longer considered a beneficiary of the estate after the current tax year.