Exchange newbie here. Our setup consists of two Exchange Servers (EX01, EX02) as part of a DAG. We'd like to further simplify this and make it a single server as we're already on Exchange Hybrid (only 30% of the mailboxes are in 365 though). We thought of moving these remaining on-prem mailboxes to EX01 and eventually decomm the EX02 and DAG.
In addition to moving the mailboxes across, what other areas and implications should I be worried/taken care of before we do this ? What'd be the best approach to complete this without impacting to the users ?