He's got entire threads on his forums dedicated to the leaks. He just doesn't put it on his front page, because he wants to stay on Nintendo's good side.
Even though Nintendo doesn't give a shit about him. (Where's his review copy?)
The only reason he got in trouble during BW's release, is because like
>>29884818and
>>29884949 said, he was actively datamining the game himself, and offering a playthrough using a blatantly pirated copy.
If Nintendo doesn't care about Polygon and Kotaku posting the leaks, they wouldn't care about Serebii, provided he's not the one leaking it himself.