Creating a GameObject using 'new' returns null when calling it from Reset() method

How to reproduce:
1. Open the "SampleScene" in the attached "case_1196137_repro" project
2. Add the "TestScript" as a Component to the "TestGameObject"

Expected results: "TestGameObject" has a "child" object attached to it
Actual results: "child" is created as a separate GameObject, NullReferenceExceptions are thrown in the console

Reproducible with: 2019.2.0b10, 2019.2.13f1, 2019.3.0b11, 2020.1.0a13
Not reproducible with: 2017.4.34f1, 2018.4.13f1, 2019.2.0b9

Additional note: The issue does not reproduce if the Reset() is called via a cog button next to a Component in the Inspector Window.