I agree with this behavior, and I can confirm it.
BUT, using your solution causes another problem:
When I open the demo, and typing Ctrl+N a new page is added
and set as selected.
Now, when the room for drawing tabs is full, and scrolling is needed, the active tab is not visible until the next Ctrl+N !
in other words, your solution affects the visibility of the selected tab in other cases.
I still think that the behavior you descrivbed is a bug, and I will find another way to solve it.
With regards,
Eran