Retiring our hybrid Exchange Server

After consulting with some Exchange experts, we have decided to go ahead and decommission our Exchange Server on-premise as soon as we get the last few email accounts moved to the Cloud.  We will add a SMTP service to another existing server for relaying emails to the Office 365 Exchange Server.  The main step we were told we needed was to update Azure AD Connect to the latest version.  Then we should be able to perform pretty much any actions we need to do using the Exchange Admin Center and Power Shell.  One of the reasons we moved to Office 365 was to eliminate the need to maintain on-premise servers. We're following through on that goal.  Thanks for the responses.