The roots/wordpress package starting with 6.0 should already omit the themes:
- With the release of WordPress 6.0
roots/wordpresswill change to serve only WordPress–no themes.
The roots/wordpress-no-content package is indeed just a bare-bones composer package that downloads the no-content WordPress ZIP from WordPress. It doesn’t install on its own on a Bedrock site, the roots/wordpress-core-installer package is also required for actually installing the raw files.
You could require the roots/wordpress-no-content and roots/wordpress-core-installer packages yourself in a Bedrock site, but this isn’t necessary as this is already handled by the roots/wordpress meta-package: The roots/wordpress package since version 6.0 indeed requires both, the roots/wordpress-no-content package and the roots/wordpress-core-installer package:
So for a WordPress core without the default themes and plugins (e.g. “Hello Dolly”), just use the roots/wordpress package starting with 6.0.