No offence PixelPower but you are using the wrong word!
It’s not official against beta.
All the releases WD puts out via their website (product pages, or via forum) are OFFICIAL!!
Unofficial ones are the B-RAD for example that are not made by Western Digital.
You should use Stable (released for wide public) vs Unstable (usually alphas and betas are unstable).
When the firmware is stable WD usually releases it as final version (Stable version). Final/Stable versions goes to public. 
