"Zen" is a lot harder to trademark than "Ryzen". Also, it sounds like "Ryzen" is their consumer product line. Their server product line might be called someth

"Zen" is a lot harder to trademark than "Ryzen". Also, it sounds like "Ryzen" is their consumer product line. Their server product line might be called something else. It makes sense to have multiple product lines with different names and to refer to the common microarchitecture as "Zen".