How to understand it(composer.json)?

Question

Yii

In short, I took the package from the vendor folder, modified it, added it to composer.json. When I try to update, I see this:
- Removing dektrium/yii2-user (v0.9.5)
- Removing yiisoft/yii2-authclient (2.0.5)
- Installing leopandro/yii2-user (dev-master dd41fcc)
As you understand, I replaced dektrium/yii2-user to your leopandro/yii2-user. But I don't understand why yiisoft/yii2-authclient was removed.

Answer 1

Most likely because it is not in the dependencies of leopandro/yii2-user

Answer 2

Guessing:
Perhaps composer decided to clean up an unused dependency you installed some time ago and removed it from the list of dependencies later.