Out of our EU-OPS manual for 737 (mixed classic/NG operation):
RHS shall closely monitor all flight instruments throughout the landing, paying special attention to the FMA "FLARE" and
"RETARD" annunciations.
RHS shall call "NO FLARE" if "FLARE" is not annunciated.
RHS shall call "NO RETARD" if "RETARD" is not annunciated.
Crew actions in case of autopilot failure at or below decision height:
• For operations to actual RVR values less than 300m, a go-around is assumed in the event of an autopilot failure at
or below DH.
• This means that a go-around is the normal action.
• However the wording recognises that there may be circumstances where the safest action is to continue the landing. Such circumstances include the height at which the failure occurs, the actual Visual references, and other malfunctions. This would typically apply to the late stages of the flare.
• In conclusion it is not forbidden to continue the approach and complete the landing when the Commander or the pilot to whom the conduct of the flight has been delegated, determines that this is the safest course of action.
This is of course valid only for fail passive planes, fail operational equipped ones (in LAND 3 status) have an alert height of 200ft below which any single failure is suppressed and automatic landing and rollout is still assured. You will get any system failure and autoland downgrade messages once your speed is below 40 kts. So no flare should not happen.