Yup, minimum speed reversion is, as c100driver correctly posted, an elevator speed mode, therefore it is not available during autopilot modes where a defined flightpath is followed.
Minimum speed protection from autothrust in ARM is however still available after G/S capture. In the THY case it wouldn't have helped however, as RA 1 below 27ft would have commanded a RETARD anyway if the thrust levers were not in idle.