$ jscodeshift -t renameDefaultStory.js **/*.story.js

input.story.js

export const defaultStory = () => <StatusDot />;

output.story.js

export const Default = () => <StatusDot />;

renameDefaultStory.js

/**
 * @param {import('@types/jscodeshift').FileInfo} fileInfo
 * @param {import('@types/jscodeshift').API} api
 */
module.exports = function(fileInfo, api) {
  return api
    .jscodeshift(fileInfo.source)
    .find(api.jscodeshift.VariableDeclarator, {
      id: {
        name: 'defaultStory'
      }
    })
    .forEach(path => {
      path.value.id.name = 'Default';
    })
    .toSource({ quote: 'single' });
};