An interesting issue that one of our senior consultants came across. Microsoft Teams users can now have PSTN Audio Conferencing (conferencing with phone numbers) and/or Cloud Phone System and PSTN Calling Plans (a real phone number and make and receive calls). However these abilities can’t be assigned unless the user account also has Skype for Business Online Plan 2 Assigned.
Users get Microsoft Teams in pretty much all plans:
Skype for Business Plan 2 is in most E plans, event E1, so it’s not a huge issue for most customers, but it is not in Enterprise F1 (which does include Microsoft Teams)
SfBO Plans against Office 365 Plans: https://technet.microsoft.com/en-us/library/office-365-plan-options.aspx
So only really a cost/licencing concern if you are using Enterprise F1 and want to use Microsoft Teams for PSTN Audio Conferences or PSTN Calling, but also a workflow consideration for enabling users in Microsoft Teams.