How to reproduce:
1. Create a new Unity project
2. In the Project window create a new Timeline asset by Right-click -> Create -> Timeline
3. Click on the created Timeline asset
4. Via the Inspector click on Reset to reset the asset

Expected result: Asset name resets to a default one
Actual result: Asset name is cleared

Reproducible with: 2020.2.0a11, 2020.2.3f1, 2021.1.0b5, 2021.2.0a3
Not reproducible with: 2020.1.17f1, 2020.2.0a10
Could not test: 2018.4.31f1, 2019.4.19f1 (Button for resetting an object doesn't work)

Note:
- Reproduces with Signal, State graph, GUI skin, Timeline
- Since the button is grayed-out in 2020.2.0a11 you can go to a different version where it reproduces (recommended 2020.2.0a14) and do the steps there, then go to the previous version. The issue should remain.