It can be a valid claim, if it pertains to discussions between a President and his staff, over his governance. It does not cover non-staff members or discussions that are criminal, in nature. In cases of criminal discussions, people are shielded from giving self incriminating testimony by the 5th Amendment to the Constitution. But, if Bannon or anyone else is granted immunity from prosecution arising from testimony on a specific subject, they have to answer questions under oath. They can be jailed for Contempt of Court or Congress, until they testify. It may take time, but, the insurrection failed and we will know the truth some day.
