To the question: Yes.
Depending on the type of vibratory actuator, you may expect regenerative voltage from the drive motor(s). Because of this the VFD must have a brake chopper and a brake resistor.
But in reality: maybe not.
Depending on the conveyor, it may be designed for a specific frequency, and it may break up if you run it at a different frequency. You have to get acceptance from the manufacturer if intend to run it at varying speeds.
Also, if you intend to vary the transportation speed by the VFD, it may not work like that. If you reduce the frequency, the amplitude may increase so that the material transports at almost the same speed.
A VFD to drive a vibratory conveyor has its use for starting and stopping quickly. Especially stopping quickly can be done with a VFD or specialised DC brake devices.