Airbus minimum groundspeed system keeps the groundspeed constant - which is more relevant for landing - rather than the airspeed
I disagree. Airspeed is always relevant and primary. GS mini just adapts the speed target to maintain that computed minimum GS that will protect you from a possible gust. So when the gust hits you, the extra knots given to your target speed by GS MINI to the are 'spent', their role has been fulfilled and the target decreases to the new value after the gust. Nice!
However it will not suffice if the gust is worse than anticipated (some think that GS MINI will protect you from any gust no matter the intensity) specially if the A/THR is sluggish.