Hi hi,
The publish boolean is now migrating to an integer. (V1.5 of transition)
And the name could also be 'State' instead of published.
For the moment, nothing changes for you because bool and tiny int are consirated the same, so don't worry.
This reason is to handle the 'archive', and 'trashed' states. (-1, -2)
In first version of 2.0, Archive and Trash are not handled, but it is open to that.
What I love with you is since the beginning, you are watching very well. You have participated and offered so many pure dev considerations. And still not all of your advices are yet implemented, warnings, php strict standards, etc...
Keep going !!
Thank you (Karma +1)