Huh. I thought it meant "beyond" and, in context, describes a means of playing the game that uses information beyond what is considered the main part of the game in order to play the game better.
It has 2-3 different meanings iirc.
True... lately, it means "build that builders mindlessly follow" and becomes popular.
Ideally there should never be a 'meta' because there being one implies that the game is unbalanced sufficiently that people who want to do well are pushed towards a certain build type.
I'd prefer that all 'sensible' classes and build types were viable - just different. Then we could choose what to play based on the play style that we enjoyed not on what had been over tuned in the latest patches.