I made a mistake here, leading astray. It's second-order cybernetics, not second order systems theory. I melted the two in my head, reason is that (Social) Systems Theory according to Niklas Luhmann [1] incorporates several parts of second order cybernetics (most of the people mentioned before show up there) and blends it all together to a point where I have difficulties to distinguish the separate parts.
This is all not 'new' in the literal sense. Luhmann died in the late 90s. I tried to come up with a spot-on-book of Luhmann, but that lead to nothing. It's all spread out (papers and books) as far as I know. There is a (transcribed) lecture given in 1992, which may come close, but I couldn't find a translated version of it.
One of the parts which hit home for me was the introduction of a differenciated form of distinctiveness, in turn partly enabled by the introduction of an observer, and observation in general. Heinz von Foerster gave an often cited sentence which I think fits the part, albeit Luhmann gurus will probably moan my simplification : "Objectivity is the delusion that observations could be made without an observer."
Apart from that, sorry for not being more helpful here.
