Good from an aesthetic point of view, but unless you use the screens to display the departures instead it's not going to make a difference is it? The adverts were a symptom, not the cause of the problems.
As we've seen from the FOI response above, NR believe the passenger flow is better with the new boards than with the old, so I think we can safely rule out a return of the old boards even if it's possible to display departures on the new screen.
I'd have thought it's just a load of entertainment industry-standard video wall panels, which aren't necessarily the most pixel-dense (128x128 in a 0.5m square is common, for example).
There's no such thing as a standard entertainment industry video wall panel. The events world use screen pitches from sub-mm to tens of mm's, entirely dependant on the usage, the bottom end of which I would certainly describe as "pixel-dense".