There are many GPS traces available in London. Unfortunately many of them only as unordered points but some intersections have a pretty good coverage of lines (e.g. at Piccadilly Circus). I used these traces to check the offset of Esri "Esri World Imagery (which (Clarity) Beta" - which is perfectly aligned) aligned (instead of ""Esri World Imagery"!) - and then compared it with OS OpenData Streetview. Both imageries match. So I guess moving building outlines in London according to this imagery is fine. If the offset is large enough, of course. Otherwise just don't bother. However since this sounds like a larger bigger task you should discuss it with the local community first.

There are many GPS traces available in London. Unfortunately many of them only as unordered points but some intersections have a pretty good coverage of lines (e.g. at Piccadilly Circus). I used these traces to check the offset of Esri World Imagery (which is perfectly aligned) and then compared it with OS OpenData Streetview. Both imageries match. So I guess moving building outlines in London according to this imagery is fine. If the offset is large enough, of course. Otherwise just don't bother. However since this sounds like a larger bigger task you should discuss it with the local community first.