If you notice your selected resources are falling out of date, the open license gives anybody the ability to change the resource as they see fit (as long as it does not have a "no derivatives" Creative Commons license). You are legally able to update the text and re-license and share your updated version with the world. In many cases, OER with a high adoption rates (e.g. OpenStax textbooks) are frequently updated and revised. The beauty of OER is that it can be adapted over time. Some instructors work with other instructors or even with their students on customizing and updating the open textbook or resources used in their classes.