I'm using Windows Defender and I didn't get any alerts about threats or anything do you know what files were removed, so I can check whether this is happening to me or if this just a progress bug
The files that got flagged for me were Unity.2D.PixelPerfect.dll, Unity.2D.SpriteShape.Runtime,dll, Unity.2D.Common.Runtime.dll, Unity.InternalAPIEngineBridge.001.dll, Unity.Mathematics.dll, Unity.2D.Animation.Triangle.Runtime.dll, Unity.Timeline.dll, UnityEngine.UI.dll, Unity.2D.Animation.Runtime.dll, and Assembly-CSharp.dll.
It might've been a case of correlation ≠ causation and I experienced the bug in addition to Norton being too eager, but I hope this helps, if only a little.