Skype for Business contacts will not migrate automatically to the Office 365 environment. Upon migration, your contact list will appear blank. However, internal VUMC address book information and your personal email contacts will repopulate.
Before your migration begins, gather and store the Skype address information for your contacts outside VUMC. Examples include: VU contacts, vendors, personal contacts, etc.
See the Pre-Migration Checklist for these and other instructions about how to prepare for your migration.