The discussion revolves around the undocumented opcodes like LAX Immediate and AAX X reg, which appear to be processed incorrectly, raising questions about their rationale for being undocumented. Users reference their discussion in the German magazine '64er' and explore the implications of using similar undocumented opcodes in modern architecture. One user proposes the idea of a Programmable Instruction Set Computer (PISC) which would utilize a programmable decoder to optimize instruction encodings based on specific use cases, suggesting that this could relieve pressure on instruction caches in modern processors, potentially benefiting VLIW architectures.