@humbug : no.. I don't think AMD can do the same to Nvidia right now. Graphics are a much harder work load. If they could do a successful chiplet design (unlikely).. Then maybe....or something else smart. They already tried wider memory and it didn't really help.
The comparisons to Intel in the PCU space are frankly irrelevant as Nvidia is not Intel. Intel experienced issued due to numerous factors combining. Intel use their on node, when 10nm kept slipping that spelled disaster. Nvidia doesn't they use TSMC or Samsung, whichever can provide the necessary performance at the right price. AMD and Nvidia have parity here. Intel also reduced R&D in CPU space in order to expand bussiness in other areas, reducing teh technological lead. Nvidia is doing the exact opposite, and is pumping in more and more R&D dollars increasing their GPU technology lead over AMD. This has reached such a point wherre Nvidia can sit back with a cheaper high yield 16/12nm process and still compete against a 7nm GPU
Any kind if chiplet design for a gaming GPU is at least 10 years away, and if we go by the number of patents and research articles released Nvidia is a long way ahead of where AMD is at. Nvidia is manufacturing functional MCM protoype GPUs and publishing details in the public space they are so confident in their technological lead here.
https://www.tomshardware.com/news/nvidia-msm-inference-chip,39780.html