It may be different now. But only a few years ago every aircraft I had worked on cancelled the stall warning below around 60kts. That's Boeing, Airbus, Cessna, all of them.
The understandable assumption was that you should know that you're stalled below 60kts. Further to this, at below 60kts, the airflow over the vane is not reliable enough to provide accurate AoA information and also I was told, to stop erroneous stall warnings on, for example, undulating runways during TO.
I know Airbus has introduced a MOD to keep the stall warning below 60kts.