it appears the default node modules we want added didn't actually get npm installed

[joeycozza]

on creation of a new app by doing
npx create-react-app --scripts-version ${locationToTarball}

[joeycozza]

So the node_modules are being installed, but the package.json file doesn't have them listed as dependencies...

[joeycozza]

using require when reading in the package.json seems like a good idea, but it uses the cached package.json, not the actual file, so even though yarn/npm install was updating the package.json, requiring it in and overwriting it was losing the new dependencies. That issue is fixed with "manually" reading in the package.json file with fs.readFileSync.