Q: Is the GPWS inhibited below some altitude on approach (similar to the A/T below 100' RA)?
Normal GPWS modes aren't inhibited
I would hazard a guess that their profile descent rates were not enough to trigger either Mode 1 or 2. They were configured so Mode 4 not applicable and no glideslope so no Mode 5.
The EGPWS does have an onboard memory so they could just be sending it to the manufacturer to have the data extracted as an additional source of information.