There is already a thread about Kernel panic on MacOS 10.15 and 10.15.1 (Radeon cards). Was affected too (2019 27” iMac with Vega 48 8GB).
A temporary solution is to switch render API to OpenGL in Graphics settings. Alternatively, setting shaders to Medium (while still using Metal API) might also help.
The main thread: SC2 Crashing on MacOS Catalina with Radeon Graphics - #36 by SpeedyRogue-178640