The contents of a homebrew-core formula definition are an implementation detail of Homebrew. Formula definitions are code. Changing that code (or its permission

The contents of a homebrew-core formula definition are an implementation detail of Homebrew. Formula definitions are code. Changing that code (or its permissions) directly is completely unsupported. Users may create their own formulas in their private taps; those will never be overwritten. If you mess with a program’s internal bits in an unsupported way (like the author of the linked blog post purportedly did), you can be happy that your changes will only get reverted on the next update and not blow up in your face.