I had a bit of fun with this video.
The sun was almost exactly perpendicular to the runway at the time of the event.
https://gyazo.com/dcbba4289e42f176e3e9e2c870fd62f3
So the airplane shadow shows us a very good indication of the airplane above the runway. And assuming the video is real speed, you can compute a ground speed.
I'm measuring 11s to fly around 930m, so a ground speed of 160-165kt.
The METAR was : METAR LPMA 261100Z 35016G29KT 300V030 9999 SCT015 17/05 Q1018=
It has a runway 05 so it had a bit of headwind component.Around 8-15kt. So that's an indicated airspeed around 170-175kt
Is that a normal speed for a 321 ? The mere sight of the pitch angle during flare tells you it isn't, even without any knowledge of this particular model.