Publishers for Educational textbooks must be fully aware that the traditional model for developing, publishing and delivering books for use in the classroom is dying, but I believe they have some time to experiment with new models before abandoning their current practices. As much as some educators and students would like to access a digital multi-modal teaching resource, it will take some time to turn the Titanic that is the publishing industry of textbooks (even if they wanted to). In recent years, I have noticed they have been offering additional interactive resources to support their traditional texts.
I think the switch is inevitable but the delivery model is still undefined and those in the purchasing role that don’t have a reliable, robust infrastructure to handle this new approach to learning may feel more comfortable with a physical resource.