How to reproduce:
1. Create a new Unity project
2. Create any GameObject and add a child GameObject to it
3. Make sure to have the parent GameObject collapsed
4. Navigate to the scene Asset in the Hierarchy and drag it to the collapsed GameObject
5. Release the mouse button and observe the results

Expected results: The GameObject is not expanded because the scene can't be added to it
Actual results: The GameObject is expanded even though the scene can't be added to it

Reproducible with: 6000.3.0a2, 6000.3.0a6
Can't test with: 6000.0.56f1, 6000.1.16f1, 6000.2.1f1, 6000.3.0a1 (Hierarchy V2 is not available) 

Reproducible on: macOS Sequoia 15.5 (M1)
Not reproducible on: No other environment tested

Note: Not reproducible with Hierarchy V1, the nested GameObject is expanded only when another GameObject is actually added as a child to it