I am making PCB where I need to turn off PNP BJT with my MCU. But my MCU is only 3.3V and it can't reach emitter voltage. So, it is good practice to turn it off by setting output pin to high impedance or should I waste my precious space on PCB for another NPN to drive PNP?
Even if you set the pin to high impedance, voltage on it must not exceed the maximum ratings in the datasheet, which is probably close to 3.3V. There could be an exception if the pin is labeled "5V tolerant".
So if the base of your PNP is above that voltage, you'll need an extra transistor to control it.
Generally speaking you should keep output voltage within Vdd or within some limit that is usually less than 6V. Otherwise the protection diode (when present, typically on non-5V tolerant pins) will conduct which will keep the PNP transistor from turning off, and could cause damage.
That way only a single component is required rather than several.