When you upgrade to SI 2016 and attempt to access Mobile Install you get the following message:
The SI feature "Mobile Install" is not a part fo your license. You need to purchase this feature in order to perform this operation.
When you click the Buy Mobile Install Seats link you are directed to our webpage but you see that you do have Mobile Install licenses available to you:
Re-register SI 2016. From an SI 2016 client click Start->Help->Register:
Click the [Register] button:
You will then see that your registration has been updated to include your Mobile Install licenses: