My Mapillary imagery here isn't quite clear enough, but I think the sign was updated from 'Except buses' to 'Except buses and cycles'

https://www.mapillary.com/app/?pKey=299618359344713&focus=photo&lat=51.5286932&lng=0.0734818&z=17&x=0.8340394498251933&y=0.5027209011081128&zoom=3

Looks like tagging was already updated to reflect this anyway

https://www.openstreetmap.org/way/138604345/history/12