Yes - it's huge. There is a bit more to it than just being on request.
The Spanish guy is quite right for the laws of his country, these rules may nor apply worldwide - and may need more than just a letter.
Like the print media, censorship of information that is in the public interest is not allowed in many places. So say of some celebrity does something asinine, Google would have the same rights to print it, talk about it etc as the rest of the media.
In this case there is a S of L for the event the Spanish guy wants "forgotten" and in his country the time for the S of L has passed.
All the same - this could be huge in the long term.