This conversation should rather go to the original changeset, i.e. https://www.openstreetmap.org/changeset/137878661
and not here.

In a nutshell: in OSM you can see the list of objects touched by a changeset below this comment, i.e. 1 way and 5 nodes were touched here.  In a nutshell, this is a change aimed at fixing your latest edit, more precisely where the EU school and the university campus meet.  They are contiguous area; I noticed you moved some points—and I think it was a good decision to rectify the "border" between them because it looked a bit weird before—and when you deleted some of those points you created gaps and/or overlaps between the two areas.  This change is here to fix this.  It was a minor geometry fix here. ;-)