Is the user manual legally considered “advertising”? If it is then you might have a good case, take WD to court and let the rest of us customers/users know how it goes.
If not then its a moot discussion. The v2.x single bay user manual has a number of errors that have been well discussed. The single bay second gen v2.x My Cloud does not support backing up to another v2.x single bay My Cloud. It does apparently support backing up to a multi bay model. Stinks that WD made this decision. Stinks that WD haven’t clarified or fixed the various errors in the user manual. But that’s the reality. If you feel wronged then take them to court.
Edit to add: There is also this standard lawyer boiler plate language at the end of the user manual…
Information furnished by WD is believed to be accurate and reliable; however, no responsibility is assumed by WD for its use nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of WD. WD reserves the right to change specifications at any time without notice.