Actually a gate or some additional transistor inserted between the uC and the transistor driver serves two purposes.
Primarily it offloads the uC pin from sinking or sourcing excessive currents to/from the load,
secondly it protects the uC pin against the Back EMF voltage usually induced in the driven coil when the current is cut off.
This voltage should be clamped to the ground potential with some Schottky diode, but sometimes both the diode and the transistor get damaged, and then you have to buy a new uC too.
So if it doesn't cost you too much, install some protection.
Most microcontrollers are protected with parasitic diodes on the die, but many people find this protection insufficient.
/yego