But it is still O
Scale, isn't it?

People do get 'scale' & 'gauge' mixed up - it's like there is no such thing really as an 'OO Scale' layout.

Doesn't stop people using that designation.
Jordan or Plymouth mad
This is a subject that comes up quite often in other scale/gauges combos
Gauge is the distance between the rails, nothing to do with scale
Whilst 0 gauge usually refers to a model in 7mm scale with a track gauge of 32mm
Scale 7 has a track gauge of 33mm but shares a scale (as ) gauge) of 7mm, but its not 0 gauge
Finescale ca equally apply to both gauge standards as far as the level of detail of the stock and scenery (less so to the track with 0 gauge)
To complicate matters you can have 0-16.5 (should be called 7mm narrow gauge) and SM32 (16mm to the foot with a track gauge of 32mm
Also you gave 0 gauge coarse, where the track standards are compatible with earlier (legacy) standards.
Or 0MF which has a 31.5 gauge
In short no wonder people get confused
John