Test if the equality operator for anything that derives from Unity.Object is still overridden. Just put the script in your project and press play in any scene to test.

UnityObjectOperatorOverloadTest.cs

// read this article for more info: https://blogs.unity3d.com/2014/05/16/custom-operator-should-we-keep-it/
using UnityEngine;

public class UnityObjectOperatorOverloadTest : MonoBehaviour
{
    	[RuntimeInitializeOnLoadMethod]
	public static void Test()
	{
		var gameObject = new GameObject("UnityEngine.Object Operator Overload Test");

		DestroyImmediate(gameObject);

		Debug.Log($"Native object {(gameObject == null ? "IS" : "IS NOT")} destroyed.");
		Debug.Log($"Managed object {(ReferenceEquals(gameObject, null) ? "IS" : "IS NOT")} destroyed.");
	}
}