Certification ...
If the teacher of the class still gets to say "this is the official textbook we will be following for this class, which you must buy", then it's not clear how that fact that there are also cheaper textbooks on an iPad will help the the situation.
And if a teacher in Texas names an official textbook then the education boardmay still require this be an approved "Certified" book with political interference on content.
Certainly if the cost of textbooks can be reduced that would be good. Although I suspect a plan to restrict second hand sales, directly or via the book becoming an interactive app. I would hope this also does not end up with "your textbook is only available on iPad and not on other tablets or (gasp) paper, so you have to buy an iPad...".