A Twitter thread about GPT-4 details has been taken down, and the original source of the information appears to be a blog post that requires a $1000 subscription. The blog post discusses the GPT-4 architecture and infrastructure, including the use of a Mixture of Experts (MoE) technique. The Twitter thread was likely deleted due to copyright concerns. The MoE technique is a machine learning approach that involves dividing a problem into sub-problems and solving each one with a specialized model.