How to reproduce:
1. Create a new project
2. (OPTIONAL) If reproducing on 2020.2 or 2021.1, you need to install "2D Sprite" package
3. Open Project window -> Assets
4. Create a new Sprite Atlas and select it (To create Sprite Atlas on 2020.2 or 2021.1, Create -> 2D -> Sprite Atlas)
5. Click the Preset icon at the top-right of the Inspector window
6. In the Select Preset window, click "Save current to"
7. Choose the location of your new Preset, enter its name, and click "Save"
8. Select newly created Sprite Atlas preset
9. Try right-clicking on "Objects for Packing"

Expected results: Context menu shows up and it's possible to exclude "Objects for Packing" from preset
Actual results: Context menu doesn't show up and doesn't let you exclude "Objects for Packing"

Reproducible with: 2020.1.17f1, 2020.2.0f1, 2021.1.0a10
Couldn't test with: 2018.4, 2019.4 (because there is no property excluding functionality)