No -- as you can see from above, Chicago Secret Service chief Martineau testified to the HSCA investigators regarding the telephone threat --- that "Kennedy was to be killed when he got to Jackson Street." The HSCA report named Vallee, an ex--Marine with a job at the warehouse overlooking the 90 degree turn at Jackson Street.
Also, we never hear about many other plots against other Presidents over the years. (Law enforcement is always reluctant to let slip info about their "methods and procedures," which could be useful to plotters.) Why is this one, by "right-wing extremists," being dredged up now, even though nothing ever happened? Meanwhile the MSM ignore what defected Communist intelligence chief Ion Mihai Pacepa said about Oswald (who actually did kill JFK and nearly killed "right-wing' General Walker) and the KGB.