if you're going to claim that something is not a valid translation of a word, you should probably know what it means first--duh?
You could go around and ask people if they know the meaning of "herald". I did, and many people did not know, but "news-teller" is definitely obvious, and as I have previously said in two other comments: while "news-teller" is not a standard or formally recognized English word, it is likely that many English speakers would still recognize and understand its meaning, more so than "herald", in my opinion, and in accordance to my experiences.
Language evolves. :)