I don't know that anything would happen. He is probably trying to sue for defamation due to income loss since he was named as a POI in the case of a little, missing boy. He and his lawyer have likely seen some holes in the articles he is suing about, imo, so decided to choose them for the defamation action.
His aim, I think, would be to try to silence the media (hahahaha) and to be awarded damages for what is considered his loss of income since that photo was published.
I have linked a pretty good article here, by the University of Wollongong, offering examples. Defamation actions take years and years. In one case, the media was able to string the case out for over 10 years. The article also says that defamation actions against the media can spur even more talk and articles - due to the matter being reported in the media - as we have already seen today.
If a resolution to William's disappearance comes somewhat soonish (criminal charges or inquest), the defamation case may not even be decided yet. The case will now go on the defamation list, from what I can tell, and be heard when the court opportunity arises.
Defamation law and free speech