There were areas detailing if people would picnic on open air grass instead under trees and also scrub areas (passing around scrub or in a forest with tall trees is not the same) and other fields. On terrain they still exist, also still visible on 2022 Geoportail.lu aerial photos. EUMapper deleted them in changeset https://www.openstreetmap.org/changeset/130455883
Some of the areas in question:
- grass under picnic tables https://www.openstreetmap.org/way/1016260446/history 
- field https://www.openstreetmap.org/way/460848100/history
- scrub area https://www.openstreetmap.org/way/290190561/history
- scrub area https://www.openstreetmap.org/way/29341608/history
Use your favorite OSM changeset analyser to check extras and further deletions.
If you care in making OSM a better map, I can only advise you to not trust this person.