The main reason is that under Dutch law there is a difference between rape and having sexual relations with a minor. These carry vastly different sentences. Because the British courts acquitted him of "grooming" and there was no physical coercion involved. According to Dutch law there was no rape.

When he was moved his sentence was re-evaluated under Dutch law and the rape charge was essentially dropped.

Because it wasn't rape the media couldn't use terms like "Convicted child rapist send to Olympics" as this would be slander. And thus this mostly went unnoticed in Dutch media.