Hi sub320,
Since this affects descent profile and deceleration. The operational impact is not huge but it does exist! Ofcourse this only affects prior slat extension, afther this you would have appr idle anyway!
And indeed the STS page is displayed to the pilot at slat extension. The ECAM is forced to display the status page, simply because it is not NORMAL. But indeed at this point the operational consequence is zero.
You would probably clear the status page quicker than you could read it.
Regards