I think they are going to continue to exist in some way or another, but I am not sure how. It seems to me that the government of the United States and the Central Bank/Federal Reserve of that country won't be foolish enough to complete replace those companies and tanking the value of the value of their shares in the stock market. If I had to guess, Visa, MasterCard and PayPal are going to work as agents or workers in the process of the functioning of the CBDC itself, by providing technological infrastructure and cryptographic security for the centralized system to work.
I am just guessing, of course, In spite of the name/term we use, just because a CBDC is issued by the Federal reserve or the central bank, it does not mean they are going to completely get rid of the middle man when one carry out transactions. It is a matter of control or the data and the flow of money, not about people saving money and erasing the middle man.