Very peculiar. Maybe someone at KRTH is trying to find out if we complainers are still listening. When Hotel California is played three or four times a day but is no longer listed on the website's playlist, every time one of us comments about it, KRTH has proof that we were actually listening. Or maybe KRTH no longer lists the song because they know how much we complain about it. They couldn't stop playing it, of course---just quit showing it on the playlist.
Since nobody in advertising or radio checks the online display of songs played, there is no reason for KRTH to hide plays.
Under the "when your hear hoofbeats, think horses and not zebras" concept, then the likely thing is that the coding of the song somehow got deleted from the metadata on the file.