You could argue that the last two sentences were removed in the book version, since the book and film were written simultaneously and the book came out later.

No, the message is from 2010; the book was published in 1982 and the film, adapted from the book, in 1984.

You're thinking of _2001: A Space Odyssey_, which even though it was written simultaneously with the movie, had quite some deviations from it.