How to drive a PMOS with higher Gate than Source voltage?
You don't need either the 10K or the diode.
The gate is insulated and provided you stay within the Vgs voltage rating, driving it higher than the source will have no ill effects.
Some MOSFETs have gate protection zeners gate to source, but that's calculated into the maximum Vgs rating. Most are rated for at least 8V.
Just make sure your MOSFET is guaranteed to be turned on adequately with the minimum 3.7V rail voltage.

Edit: To cover situation with MCU not powered:



simulate this circuit &ndash; Schematic created using CircuitLab