IE11でarrow関数の変換ができない @babel/plugin-transform-arrow-functions が機能しない

ReactでIE11向けサイトを作成しているのですが、
Chromeでは使用できるarrow関数がIE11では構文エラーとなってしまいます。

@babel/plugin-transform-arrow-functions はarrow関数をfunctionに変換してくれるプラグインだという認識ですが正しいでしょうか。
buildした際にarrow関数が残ってしまいます。

設定は下記になります。

package.json

  "dependencies": {
    "@babel/runtime": "^7.2.0",
    "@fortawesome/fontawesome-svg-core": "^1.2.8",
    "@fortawesome/free-solid-svg-icons": "^5.5.0",
    "@fortawesome/react-fontawesome": "^0.1.3",
    "aglio": "^2.3.0",
    "axios": "^0.18.0",
    "bootstrap": "^4.1.3",
    "bootstrap-daterangepicker": "^3.0.3",
    "echarts": "^4.2.0-rc.2",
    "echarts-for-react": "^2.0.15-beta.0",
    "getstorybook": "^1.7.0",
    "global": "^4.3.2",
    "jquery": "^3.3.1",
    "mobx": "4",
    "mobx-react": "^5.3.6",
    "moment": "^2.22.2",
    "prop-types": "^15.6.2",
    "react": "^16.6.1",
    "react-bootstrap-daterangepicker": "^4.1.0",
    "react-content-loader": "^3.4.1",
    "react-dom": "^16.6.1",
    "react-global-configuration": "^1.3.0",
    "react-icons": "^3.2.2",
    "react-loading": "^2.0.3",
    "react-loading-skeleton": "^1.0.0",
    "react-router-dom": "^4.3.1",
    "reactstrap": "^6.5.0"
  },
  "devDependencies": {
    "@babel/core": "^7.1.5",
    "@babel/plugin-proposal-class-properties": "^7.1.0",
    "@babel/plugin-proposal-decorators": "^7.1.2",
    "@babel/plugin-transform-arrow-functions": "^7.2.0",
    "@babel/polyfill": "^7.2.5",
    "@babel/preset-env": "^7.1.5",
    "@babel/preset-react": "^7.0.0",
    "@storybook/react": "^4.0.8",
    "babel-loader": "^8.0.4",
    "babel-plugin-transform-runtime": "^6.23.0",
    "css-loader": "^1.0.1",
    "ol": "^5.3.0",
    "style-loader": "^0.23.1",
    "styled-components": "^4.1.1",
    "uniqid": "^5.0.3",
    "url-loader": "^1.1.2",
    "uuid": "^3.3.2",
    "webpack": "^4.25.1",
    "webpack-cli": "^3.1.2",
    "webpack-dev-server": "^3.1.10",
    "write-file-webpack-plugin": "^4.4.1"
  },

webpack.config.js

// webpack.confing.js

const path = require('path')
const WriteFilePlugin = require('write-file-webpack-plugin')

module.exports = {
  mode: 'development',
  entry: ['./src/app.js'],
  output: {
    path: path.resolve(__dirname, './'),
    filename: 'public/build.min.js'
  },
  plugins : [
    new WriteFilePlugin(),
  ],
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        loader: 'babel-loader',
        query: {
          babelrc: false,
          presets: [
            ['@babel/preset-env', {
              useBuiltIns : 'usage',
              targets : {
                browsers : [
                  'last 2 versions',
                  'ie >= 11',
                ],
              },
            }],
            '@babel/preset-react',
          ],
          plugins: [
            ['@babel/plugin-proposal-decorators', {
              legacy: true
            }],
            ['@babel/plugin-proposal-class-properties', {
              loose: true
            }],
            ['@babel/plugin-transform-runtime', {
              regenerator : true,
            }],
            ['@babel/plugin-transform-arrow-functions', {
              spec : false,
            }],
          ]
        }
      },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader?modules']
      },
      {
        test: /\.scss$/,
        use: ['style-loader', 'css-loader', 'sass-loader']
      },
      {
        test: /\.(pdf|jpg|png|gif|svg|ico)$/,
        use: ['url-loader']
      }
    ]
  },
  resolve: {
    extensions: ['.js', '.jsx']
  },
  devServer: {
    contentBase: path.join(__dirname, './public'),
    compress: true,
    port: 9000
  }
}