IMHO having this as a rule that keys in dictionaries are sorted alphabetically can be a valid rule. But this should be enforced in tooling, not "rules", and not through micromanagement. Much like using opinionated code formatters - like `prettier` you mention. It makes lives of everyone easier down the line.

Sometimes this comes from years of experience (mostly pain ;)). Some leaders, while coming from a good place - I want to help you, and others, avoid pain in the future - communicate it very badly - do it like that... because I say so!