Bonjour David: A TAZ is a large area Zener specifically rated and tested on standard pulses with defined wave shape, current etc.
TAZ have specified clamp V and certain currents, but cannot dissipate long-term. The large die in a small package was developed at General Semi decades ago. Yes they are Zeners but not interchangeable!
In the case of gate protection, a TAZ is not usually needed and a Zener can serve as the current is limited by the driver.
Beware of the Zener shunt capacitance on the driver performance.
Bon chance
Jon