This is very odd and you may want to open an SR to get to the bottom of it.
Increasing the boot-up start delay appears to fix the issue,
I hope this defect is addressed in the next release of VCSA.
1. Modify statsmonitor service config for vMon to set higher startup timeout:
sed -i '/StartTimeout/d' /etc/vmware/vmware-vmon/svcCfgfiles/statsmonitor.json
sed -i '/ApiHealthFile/a "StartTimeout": 600,' /etc/vmware/vmware-vmon/svcCfgfiles/statsmonitor.json
2. kill -HUP $(cat /var/run/vmon.pid)
3. # Stop and start statsmonitor service explicitly.
/usr/lib/vmware-vmon/vmon-cli -k statsmonitor
/usr/lib/vmware-vmon/vmon-cli -i statsmonitor
Now reboot the VCSA and check after 10-15 mins and the Statsmonitor Service should start up automatically.