True, it does say that... Why would that be the case, though?
At any rate, having had that AoA disagree warning (limited to above 400 ft) would not have saved these planes, it seems to me. Having had an AoA disagree warning on the ground might have.
It's because you have to have moving air for an AoA sensor to work. Unmatched sensors when there isn't enough air movement for proper operation doesn't mean anything.
But the air certainly moves fast enough at the moment of taking off, and if the sensors are sensibly sensitive, they should register AoA well before V_1.
EDIT to add:
Hm, Boeing states:
"During rotation, pitch angle is the critical parameter that ensures tail clearance. Once the airplane is airborne and at a sufficient altitude where ground effect and crosswinds do not affect the sensor reading, AOA will provide valid information."
Looking at the FDR for Ethiopia [1], it looks like the AOA sensors disagreed 2 seconds before they left the runway.
The sensor disagreement happens after 05:38.43, they started climbing at 05:38:45 and were at 1000ft at 05:39:06 ish if I am reading the PDF image correctly.
