DC decommission, Keytab and kerberos

Hi team,

We have two domain controllers in the HO site running Windows server 2012 R2. We're in the process of upgrading the environment to WS 2016. We have completed one server and one is remaining.

The decommissioning process includes

• Decommission of DC
• Re-formatting
• Promoting the fresh server to be DC

Currently one server we have done the above to bring it to 2016. One server is remaining.

I would like to clarify the below;

1. Currently keytab files are created for several 3rd party applications. What would be the impact if we decommission the last WS 2012 R2 server?
2. Will there be any impact on kerberos certificates or any related? Do we need to backup or reconfigure it or anything?

Thank you.
Jude.