the current headphones in the First Cabin are cheap black plastic and do not look much different to these Meridian branded ones ! if one were to "pinch" a set the connector may prove troublesome - BA use a 2 or triangular 3 pin.
I recall Emirates started to offer B&W noise cancelling headphones in their first class cabin around 6 months ago but I never tried them.

Meridian M80 & Meridian Ellipse
Gone:7200SEs,808v6,G95,MC200,MS200,218,210,MD600,F80, Explorer 1,201Pre mk3