Generating an Ionic Angular app defaults to Angular 8

When I generate a blank Ionic Angular app with the latest ionic/cli package, I get Ionic/Angular ^5.0.0 in the package.json file as expected. However the Angular packages are still ^8.x.x.

Am I doing something wrong?
And is there a guide how to migrate to Angular 9 in an ionic application?

I would suggest the generic Angular upgrade guide.