We're currently looking into a Yammer network merge, but we're also changing the users UPNs in the future. The on-premises AD accounts will be edited and later on synchronized to Azure AD. Everyone will get the same email address after the UPN change.
Should we proceed with the merge or is it better to wait untill we have made the changes to AD? We have also not yet enforced Office 365 identities in Yammer and would like to include that as well. When should we start enforcing the O365 identities?