My Cloud EX2 Ultra Compatibility with Red Pro Drive

I see from the Compatibility List that WD6001FFWX (6GB Red Pro) & WD80EFZX (8GB Red) is support but no WD8001FFWX (8GB Red Pro). Is that any reason why not support?

As per My Cloud EX2 Ultra User manual, WD recommends inserting WD Red hard drive for better performance. WD Red Pro comes with 7200 RPM which require more power as compared with the WD Red 5400 RPM drives.