According to early testing in the Netherlands, Disney+ may not work on a number of popular consumer devices. Much like other streaming services, Disney is using DRM, or Digital Rights Management, to help prevent piracy, but is using a much more strict version.
Disney is using a DRM service provided by Google called Widevine, which offers three different levels of security. Currently, Disney+ is using level 1, which is the strictest level and is not supported by Chromebooks and many older Android devices.
Streaming services like Netflix use level 3 DRM, which doesn’t support HD streaming on mobile devices and some Android devices. Disney+ using type 1 allows it to stream in HD, but limits the number of supported devices.
It is unknown at this time if the use of level 1 is just for the testing period so that video isn’t leaked, or if that will be the standard upon the full launch next month.