MacRumors reports that new references to AMD processors has been discovered in the beta version of macOS 10.15.4.
New References to AMD Processors Discovered in macOS 10.15.4 Beta
Over the last few months, an increasing number of references to AMD processors have been uncovered in macOS Catalina code, starting with the 10.15.2 beta in November and now continuing in the 10.15.4 beta.
New References to AMD Processors Discovered in macOS 10.15.4 Beta