CT, an intriguing analysis (#1573).
The logic given is according to Honeywell, but the precise integration and configuration for the 777 is not known.
It would be unusual to use a single switch, the RAAS description of 'WoW' is more likely to be a generic input term. The aircraft output would have be chosen by Boeing, which probably involves at least both main wheels. Some aircraft use a 'two out of three' logic to provide additional integrity for WoW or specific systems' selection.
It is even feasible that the 777 RAAS installation chose a logic which provided RAAS alerts until all wheels are on the ground, and perhaps with pilot reaction time, represents the last chance of a rejected landing. I think that is is too much to suppose and it would further complicate the contradictions and confusion with SOPs and TOGA.
The primary inhibition on the RAAS alert appears to be 'less than 5ft', but this is not necessarily supported by the FDR. However, without knowledge of the FDR update rate for an assumed 'low priority' advisory RAAS parameter (~4 sec?) there is no certainty.
Also, it would be unusual to consider WoW as a backup for loss RA when the RA is required previously to enable the long landing alert (<100ft); I suspect that this is associated with other parts of RAAS.
The details of 777 TOGA inhibit are unclear; the FCOM suggests WoW (but which aircraft logic?), yet there is technical opinion that it occurs at <2 ft RA (and what's the back up system for a failed RA?).
This whole issue highlights the importance of management requiring a thorough understanding of 'add-on' systems and the host aircraft. And particularly the interface and interactions before choosing an operating procedure (N.B Honeywell does not require a GA).
The alerting system and aircraft manufacturer also have roles in this area, as should the approving regulator. Whilst independently each system / aircraft function meets the certification requirements, together, the previously assumed risks (certification basis) in new 'improbable', yet relevant situations can be very significant.