Certainly not fake, I believe it to be the same version, Cubase Audio v1.1 aka Cubase Audio Falcon v1.1 with the capability to integrate with Falcon, or ST, STe and TT regarding audio with the CBX. Regarding manual, I think you are somewhat correct, I think it would be the v1.1 manual, or potentially v1.1 addendum. As you say Cubase Audio Falcon v2.xx do not appear to mention anything regarding CBX.
Atari Falcon 14mb, 68882, Dual 8gb CF, Steinberg FDI & Analog 8
Atari Jaguar, Rotary controller, Skunkboard & Cat Box
Atari 520STFM 4mb, TOS 2.06 switcher, OverScan, GigaFile, PARCP-USB, Unicorn-USB, System Solutions MiniS HD, SyQuest drives, ICD Link II, PhatBoy MIDI Controller, Philip Rees 5M MIDI merge box, SoundPool MO4, Steinberg MIDEX, SMP II, Emagic Log 3, C-Lab Unitor 2, Combiner & Export expanders