I don't know if this has already been reported, but I couldn't find it.
Using 2.44d, load a folder containing FLAC files with embedded album art. Select a file ( or all files for that matter ). The album art appears correctly. Remove the file(s) and the album art remains and stays displayed until another folder is loaded and a file selected.
This doesn't happen with 2.44, where the image disappears when the file(s) is removed. I think it started happening before 2.44d, but I'm not sure when exactly.
You are right, but it is not only an album art problem.
If you select one file, press Del to remove it from the list, the whole tag panel view is not updated.