Vilas
In the EGPWC schematic In the FCOM there are only two possible inputs from the SFCC:
FULL or CONF3
If it was actual, any abnormal configuration would inevitably lead to a GPWS during short final unless FLAP MODE OFF. But we see that in yellow remaining we push FLAP 3 mode ON. So I would say, without betting my savings, that GPWS mode 4 is governed by flap lever position rather than actual flaps/slats.
Still, blue remaining procedure calls for landing conf 3, but GPWS will be OFF, so I don't understand the reason for the conf 3 when in many cases nothing at all happens when moving the lever to 3. Moreover, by doing so displayed VFE is more in error than with the lever at 2.
Maybe a simulator experiment can give a clue on the reason, if you have the chance...