I know this topic has been quiet for a couple of months, but I ran into the same issue on my MSI GS65 Stealth. I found some information on the Arch Linux website (search for “MSI GS65” and check out the “Function Keys” section) and also on Ask Ubuntu (search for “MSI GS65 wifi hardware switch disabled after suspend”) about enabling the airplane mode function key combination under Linux.
To summarize what I found, add acpi_osi=! acpi_osi='Windows 2009' to the GRUB_CMDLINE_LINUX variable in /etc/default/grub, and then run sudo update-grub and reboot your system. This should enable the airplane mode function key combo (Fn+F10).
With the airplane mode function key enabled, it is now possible for me to recover from the hardware locked wifi issue by pressing Fn+F10 twice - not the most elegant solution, but at least I don’t have to reboot.
Your MSI P65 is very similar to the GS65, so the same procedure could work in your case. I hope this helps somebody.