Environment
O365 and Hosted Lync or Skype for Business
Resolution
Disable Lync Online in Office 365 Admin Portal at:
Remove Lync Online from the Domain Purpose (do this for every domain):
In Office365 Admin Center, click on Domains in the navigation pane on the left.
Click on the domain to select it.
Click the Manage DNS link on the right side of the screen.
Click on the Change Domain Purpose link in the Domain Purpose section.
Unselect Lync Online or Skype for Business for instant messaging and online meetings
Click Save.
Disable Lync Online License for each user (do this for every user):
In Office365 Admin Center, click on Users in the navigation pane on the left and then select Active Users.
Click on the user to edit it.
Click on Licenses.
Expand the License Type assigned to the user (ie E3 or E4) to display the list of sublicenses available in that plan.
Unselect Lync Online Plan 1 or Plan 2/ Skype for Business Online Plan 1 or Plan 2
Click Save.