How to reproduce:
1. Open a Unity project with the Editor that contains Personal license (Unity --> Manage License for Mac users)
2. Go to Help -- > Manage License
3. Select Activate New License
4. Enter your Plus/Pro serial number and press Next
5. Observe the title of the Editor at the top left

Expected result - Editor skin changes and so does the title of the Editor
Actual result - Editor skin changes, but the title still says "Unity... Personal"

Reproducible with - 5.6.3p2, 2017.1.1p1, 2017.2.0b11, 2017.3.0a7

Note - Does not reproduce on relaunching the Editor