This post of Svetlana explains it a bit: Saving Preset without the Crop or Local Adjustements
If no local adjustment was ever applied to a picture the preset will have none. If local adjustment was applied and removed, the preset will have the „remove“ setting. Scroll down to see how to fix that manually.
So it is correct that not all presets will remove local adjustments. But the UI has no way to tell them apart or change this behavior.