Thanks for your question.
The Qlik Sense Hub will have a new stream created - QlikView Documents Section - so you are correct with your last assumption: "All the QlikView Dashboards will be published at one place in the unified hub"
The QlikView application will work and display the same as it it already does in QlikView - because it is just a link to the QlikView document that would have been launched from the accesspoint - passing the same credentials to the accesspoint.
Here is a video on the topic:
Here is the help topic:
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