@ Bearfoil: Also, a rapid and consistent increase in a/s could trigger WindshearAlert. It could also trigger OverSpeed alert, etc. These artifacts are present in the ACARS
I don't think the Windshear Alert can trigger at all. It only actively (assuming the same piece of kit is used on the 'Bus in AF design spec as in many other airlines) starts looking for windshear when the RadAlt is below 2300ftRA. That is when warnings can be given.