public static bool pipelineSwitchCompleted { get; }

The value is if the render pipeline is in the process of being switched. The value is if the switch has completed and the render pipeline is ready for use.

Unity doesn't switch the render pipeline immediately when you set GraphicsSettings.currentRenderPipeline or QualitySettings.renderPipeline. Unity only initializes a new RenderPipeline instance the first time any Camera renders after you set a new RenderPipelineAsset. You can use this property to check if this has happened and the switch has finished.

You can also subscribe to the RenderPipelineManager.activeRenderPipelineAssetChanged and RenderPipelineManager.activeRenderPipelineTypeChanged callbacks on the RenderPipelineManager if you want to receive a callback instead of using a property.