The FCOM describes the A/THR when in SPEED mode will limit speed to VMAX even when the target speed is above this value. It doesn't say the same for THRUST mode ( I.e At Take off) however I tried this scenario in the simulator and at Flap 1 initially the auto retract occurred at 210 kts, then pitch up to maintain 230 kts and after lever off thrust reduced and 230 kts was maintained despite of a managed speed target of 250 kts.
I wouldn't try this inflight however as manoeuvres / turbulence etc would probably create a overspeed condition!