Is it safe to update to OS Catalina while running Logic Pro X version 10.4.6?
All the negative reports I could find center around Catalina's lack of support for 32-bit code and heightened security that may affect 3rd party FX, plugins, and other software and hardware some folks use to supplement Logic Pro X.

If you use 3rd party software or hardware, check with the developer or manufacturer to make sure it is compatible.

ProToolsExpert has a searchable Ultimate Pro Audio Guide to macOS Catalina Compatibility chart with 152 developers listed.