Sometimes you come across things that have the potential of letting fecal matter hit the rotary impeller.
Let me warn you.

Imagine you have successfully completed the ESXi upgrades, systems are back alive, nothing broke and everything is fine and dandy.
After a while you are thinking “shit I forgot to update the VMware Tools on those Servers”.
In this purely hypothetical scenario you connect to the Hypervisor select your VMs, right klick and select Guest > update VMware Tools.

A couple minutes later the VMs reboot. (!)
No warning, no check if that is fine with you, the VMs just reboot.

Conclusion: To make sure you do not melt some customers productive systems, plan your VMware Tools updates along with the ESXi upgrade downtimes.

Holy shit,