Please familiarize yourself with the meaning of highway=pedestrian and area=yes before continuing to remove the tags from pedestrian plazas.  Please take a look at https://wiki.openstreetmap.org/wiki/Tag:highway%3Dpedestrian#Squares_and_plazas 

highway=pedestrian is entirely appropriate for this and similar features. It is a paved area, built for and traversal by people on foot.