These AoA are likely very close to L/Dmax, but I imagine that in each aircraft, test teams built in a pad to ensure acceptable handling qualities were maintained. This would be to protect against moving in-and-out of backside and frontside regimes. That said, none of the flight manuals I have read corroborate such a hunch, but I know that in evaluating "Steady-state flight-path response to pitch controller," the MIL-STD evaluation criteria requires that an "aircraft remains tractable at commonly encountered off-nominal speeds." In this case, off-nominal is 5 knots slow. Given that airspeed behavior becomes unstable at speeds below minimum drag speed, and that L/Dmax occurs at Dmin, it makes sense to build in a buffer, landing performance notwithstanding, and thus, published flight manual approach speeds are above L/Dmax.