Once created a "main" VM we keep it alone to embed Windows updates. Then we clone this into a "service" VM which we convert into a Template to deploy Linked Clones.
Now, what is the Best Practice to update WIndows OS for the Linked CLones?
So you want to update all linked clones?
You need to understand first what means linked clones:
Temaplate virtual disk is used into each related clone. What is added after cloning procces it's writed into a different part on the disk so dosen't exist any relation between link_clone1 and link_clone2 only base virtual disk who contain win and probably other tools (np++ chrome..)
I know only 2 solution for your problem:
1.Manualy on each vm (you can create a snapshot because some win update can create low performance exp for some bussines aplication)
2.Automation. You can create a shell script who can be embeded into all templates and who can be run after that by some automated procces
(ex Ansible, Operation Orchestration by HP (Microfocus in present) or other solution )