You're correct up to a point. Yes, Vinnie and Jeff Berlin were looking for extra money. Yes, Zappa cancelled the electric portion of the recording. Yes, Vinnie never worked with Zappa again.
What you left out... At this time, Vinnie had become an in-demand studio player. It's what he wanted to become when moving from Boston to California in the first place. His decision to QUIT Zappa's band was based on the touring schedule of Zappa and him not being available to work in the studio.
Originally Posted by Ian Ballard
Jeff Berlin and Vinnie called Frank's management and tried to make a secret deal with the attitude of "don't tell the other guys" . Frank cancelled the use of the rock band with the orchestra and just finished the classical tour without them. And he never employed Vinnie's services again.
Oh, and after having just read that chapter in the "Real Frank Zappa Book", it appears as if Frank does mention Chad Wackerman.