Is it safe to drive P-channel MOSFET gate directly from an MCU pin and 12V pull-up?
Good question. You are wise to ask.

This is not recommended. Sometimes MCU inputs specify that a certain amount of current can be injected through the protection diodes. You will have to check the MCU you eventually settle on. Select a pullup that will insure you stay under the maximum allowable current. But it would probably just be easier to add an additional NPN or N-channel (BSS138) to pull down the gate of the PMOS. Then there is no problem and you are free to choose any MCU, because it will never "see" 12 V.

Edit: I was only thinking  about damage to the MCU. But @abdullah kahraman raises another equally important point. The diode current will also cause the PMOS to turn on. So this just plain won't work.