It's in there, you must have just missed it.Milan was sampling last year, if I recall correctly. I think you're misinterpreting the first slide.
edit: now that I think of it, where did you even get that first slide? It isn't from the slide deck I linked.
If you go by when AMD starts sampling to partners, then Zen4 in 2021 is a possibility as key partners start to get samples well ahead of launch but even then, you're back to Zen3 being an end of 2020 product with earlier sampling and Zen4 being a 2022 product with earlier sampling, just like their roadmaps show, even though I can see where you and NBC got confused. The roadmap isn't supposed to line up at the ends, the dates at the beginning and end are more like bookends.
The purpose of these road maps was to show partners and investors the time frame they are on for Zen iterations from Zen 1 to Zen 4. Basically they are just saying between 2017 and 2022 they will have Zen 1 - Zen 4 released. That's it. AMD also provided context during the presentation that isn't found in the slides to better understand the roadmaps, such as:
For the client roadmap which ends with Zen3 and the year 2021. So there's wiggle room in these roadmaps and they shouldn't be read as hard launch time frames but rather general guidance of availability.Tom's Hardware said:The company says the first Zen 3 chips will land during the tail end of 2020, but the chips will be "fully in the market" for all segments by the end of 2021.