When you enter any of the lounges, the long skirts do create a more formal impression. But CX could have done this for both aisles.

I had a short chat with one of the SPs and she said the whole idea of the long skirt, and for them to only stay on one side of aircraft during service was a "concept" introduced during the development of the current uniforms. (Is this true? How was it then during the days of the purple/ eggplant uniforms? Or in the days of the bowtie-uniform?).

I only had one flight on CX business as a boy, but during the bowtie uniform days, I remember two FAs serving the right side - one wearing the navy blu blazer, and the other one red.