The Verge has a report that Tim Cook has stated that Apple will not combine a MacBook and the iPad. Here is a link to the Verge article.
When traveling: The iPad Pro for me is a portable replacement. I am very happy to travel with one charging cable (lightning) that charges both my iPhone and iPad.
All about the Apps: The iPad Pro functionality has mostly to do with the power of the apps that you need and the apps that are available. For me I need at the ready; Word, Excel, Powerpoint, Keynote, Canva, Email, Slack, Twitter, Facebook, Linkedin, Chrome, iMessages and Skype. The iPad has great versions of all these apps.
All about the FOCUS: For me, when I am working on my MacBook, I notice that I have tons of apps, windows, chats all open at one time. I have an email 1/2 done, a word doc 1/2 done and then a notification comes in and I am using gestures to swtich between things. I have only been using the iPad Pro for two days, but I find it very comfortable using iOS, by having all the apps in full screen I am able to focus on the task at hand.