What is the point then in up-branding a chip with identical performance that spans two different process generations?
Do the two different generations have different TDP envelopes? I though the 5xxx and 4xxx series both use Vega - what is the appreciable product difference between Zen 2 and Zen 3 if the performance/TDP/graphics performance is the same?
I think you are kinda answering your own question here? the difference between Zen 2 and Zen 3 is that they are different architectures. there may not be an appreciable product difference between a mid/high bin Zen 2 part and a low/mid bin Zen 3 part. this is why we have SKUs; they take a spreadsheet worth of details and compress them into a rough total ordering of price/performance.
the point is that it's annoying to compare 4000 series parts against 5000 series parts to figure out what is the best budget AMD CPU. outside of enthusiast circles, no one cares about being on the latest architecture. they care about what is currently the best performing part within their budget.
Do the two different generations have different TDP envelopes? I though the 5xxx and 4xxx series both use Vega - what is the appreciable product difference between Zen 2 and Zen 3 if the performance/TDP/graphics performance is the same?