For reference:
panic: vm_fault_lookup: fault on nofault entry, addr: 0xffffffff83cf7000
db:0:kdb.enter.default> bt
Tracing pid 1 tid 100002 td 0xfffffe00098b2ac0
kdb_enter() at kdb_enter+0x32/frame 0xfffffe000859d920
vpanic() at vpanic+0x182/frame 0xfffffe000859d970
panic() at panic+0x43/frame 0xfffffe000859d9d0
vm_fault() at vm_fault+0x15da/frame 0xfffffe000859dae0
vm_fault_trap() at vm_fault_trap+0x71/frame 0xfffffe000859db20
trap_pfault() at trap_pfault+0x22d/frame 0xfffffe000859db80
calltrap() at calltrap+0x8/frame 0xfffffe000859db80
--- trap 0xc, rip = 0xffffffff83cf7fb0, rsp = 0xfffffe000859dc58, rbp = 0xfffffe000859ddb0 ---
_end() at 0xffffffff83cf7fb0/frame 0xfffffe000859ddb0
sys_reboot() at sys_reboot+0x2d2/frame 0xfffffe000859de00
amd64_syscall() at amd64_syscall+0x12e/frame 0xfffffe000859df30
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe000859df30
--- syscall (55, FreeBSD ELF64, sys_reboot), rip = 0x2739fa, rsp = 0x820a15be8, rbp = 0x820a16010 ---
This system is an ESXi VM. Given the panic points to a memory issue, it's more likely to be an issue with the VM itself and not the upgrade. FWIW I have not run into this on ESXi 7.