While the above descriptions are entirely correct, maybe they overcomplicate things and the simple benefit is hard to see.
You're at 200 ft with 30 kt headwind, however THR reported component is only 6 kt. At a certain time, you are about to lose 24 kt and it may come quite suddenly. So you are facing 24 kt drop of IAS unless you compensate with thrust, which of course is a second nature (no pun) and normal, required piloting skill. You arrive to 15 ft with Vapp 130, albeit with little more N1 added than was previously required to maintain Vapp on final.
With the same scenario, on AB the Vapp is 130 kt but as you decelerate in managed spd (VNAV SPD was the B term if I remember) the SPD target stucks at 130+24=154 kt and so you fly, N1 stable. As you cross the shear layer, headwind diminishes and your IAS drops by 24 knots. Voila, here's your Vapp exactly as you wanted and exactly where you needed.
If you do not like the behaviour, just go to selected speed (FCU) but be prepared to increase thrust to compensate for the shear.
Frankly, it is a matter of technique not technology. Either you fly speed and add thrust to flare to maintain Vapp, or you fly energy and watch ASI unwind to target. It works quite well and is no groundbreaking feat, AB had been around the block for 22 or so years.
Yours,
FD (the un-real)