No. The second gen single bay My Cloud did not officially support adding additional third party modules/apps in OS3. One had to modify or trick the firmware code (see this link) to remove the block and enable the ability to add third party modules/apps in the OS3 v2.x firmware.
The WD knowledgebase link you posted even states OS3 didn’t support third party apps on the single bay units.
OS3 to OS5 Feature Differences
- Not all features listed are supported on all My Cloud product models
- Single Bay My Cloud in OS 3 does not support the installation of 3rd party apps
- Integrated apps in OS 3 (Backups, iTunes, DLNA, etc…) are now installable from the Apps tab
