What makes you think Petraeus' testimony would be any different than what Obama or Clinton have already said publicly? Petraeus was going to testify until word got out the Republicans knew about the affair and the FBI investigation. Then Petraeus quit.
I don’t know what his testimony would be. I do know Hillbilly will lie and the more she knows about about any other testimony the more she will craft her lies to fit it.
Petreaus would assume the Intel committee and President knew all along.