What sort of twisted mind do you have to have to link a perfectly reasonable and sensible comment by a German manufacturer with another manufacturer's product in a recording studio in the UK? Where is the connection? Why not moan about PMC or ADAM, which you will also find at Abbey Road? It's not a marketing thing, they've been using them for over 30 years. My son, who is in the industry, I remember him telling me about 4 or 5 years ago he was blown away by the B&W at Abbey Road.That quote references a hypothesis long ago falsified by the NRC/Harman blind test data, which showed large (not universal, but supermajority) consumer preferences for loudspeakers with flat and smooth on axis response coupled with smooth off axis response. That is to say, what Neumann offers.
Pragmatically, that statement is really Neumann shouting “ignore that promotional deal B&W has with Abbey Road and similar marketing ruses - you really want to monitor on neutral speakers!”
The research you refer to is not universally accepted, even by makers of some of the best studio monitors who also make domestic speakers, nor does the logic work that the flattest speakers will be the best for domestic playback. It doesn't work in practise either.