In a new video that looks back on last year's launch of the first AMD Ryzen processors, a chief architect of the Zen architecture reveals work is already in progress on the Zen 5 architecture.
The second-generation Ryzen processors will be launched in ten days, these are based on the Zen+ architecture. Previously, the company already talked about Zen 2 and Zen 3, these will both be fabbed on a 7nm process.
The video's disclaimer confirms Zen 5 is an internal codename for a future generation of Zen architecture and is subject to change. Presumably, there is no Zen 4 because this is an unlucky number in Chinese culture, similar to how the number 13 is disliked in the western world. This causes some manufacturers to skip the number four, but it's not universal as Intel had the Pentium 4 and more recently Apple had no problem with its iPhone 4. Based on current roadmaps, this implies Zen 5 shouldn't be expected before 2021.