Stall is irrelevant to speed.
The stall warning can still come on 5-10kts
before the stall. The speed at which the aircraft stalls in its current configuration or load is irrelevant but the corresponding angle for the warning activation will still be relative to the current dynamic stall speed. So the statement above is correct and true, the stall warning activates 5-10kts
before the stall, for the current flight condition.