In my many years of experience with Android, I can confirm that when the adb binary is out of date it will report offline. In newer versions of the adb binary, the device state UNAUTHORIZED exists.
A patch is available upstream for this issue. Latest version of adb can be found at https://android.googlesource.com/platform/system/core/+/master/adb/ Specifically, patch d5fcafaf41f8ec90986c813f75ec78402096af2d is helpful.
