With the autothrottle armed (MCP) and no autopilot or autothrottle engaged, with 3 or 4 engines, normal EEC mode, the autothrottle remains ARMED (available for a 'controlled' 2000 fpm climb) until 2 secs after 5'R (when the TOGA switches are inhibited) until 3 secs after 5'R in the climb. If there is no valid radalt signal presumably the inhibit doesn't occur?
So, as I understand it, the AT remains armed throughout but the TOGA switches themselves are effectively unpowered.
Not sure if that answers your original question. It's been a while......