We’re going to need a concept of ‘post-development’ to make sense of what comes next

I think that wouldn't be needed for a long time yet, there is still a lot of room for even current development in China, later would come improvement, modernisation and developing other countries etc. I don't think, barring some worldwide catastrophe, that development will ever reach the levels of what libs always claim about socialism, stagnation. Or even what utopian socialists say about just stopping.