One of Elvis' favorite movies was "2001: A Space Odyssey". The theme music for that movie was 'Also Sprach Zarathustra', a 19th-century Richard Strauss tone poem. It is also the theme music that Elvis opened all of his concerts with in the 1970's. Why would Elvis link these things together?
What room did Elvis supposedly die in? The bathroom. In the movie, "2001: A Space Odyssey", the character named Bowman first realizes that the aging process is catching up to him while he is in the bathroom. He appears shocked about being middle-aged. Elvis was once quoted as saying, "I don't want to be 40 and up on some stage singing Heartbreak Hotel". It is in the bathroom that Bowman puts his plan into action to die and be reborn.
Elvis wasn't hinting to the year 2001 but rather to the symbolism and connection he had to this movie.