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I'm puzzled why you would expect to be able to emulate older processes in newer fabs.
They don't just keep shrinking the geometries. The chemicals used, the etching techniques, everything changes over time. You probably couldn't even find the database needed to generate a new mask set that would fit in the modern equipment.
Too much exposure to software, I guess!
To a software engineer, using a virtual machine to emulate an older architecture is a commonly used approach, and gives "near perfect" albeit not 100% exactly the same result as the original designs - but "good enough for Australia", even though the new technology it runs on has absolutely nothing to do with what was available back when the original was designed.
It doesn't seem beyond imagination that an older part could be emulated with a newer design, one that might have a completely different schematic diagram that suits the newer processes, yet ends up behaving like the older part at least on a "good enough for Australia" basis?