GD's message is very cryptic. Plus he's our intel guy so he probably knows something we don't.
By comparing with SDP, I'm guessing that he referred to CSJ going in and ousted CST, thereby changing SDP's fabric quite significantly. Plus he said he only trusts JBJ, CST and SL. Which means CSJ could very well be a high-profile mole tasked to wreck SDP, taking on the antagonistic approach and causing SDP to lose credibility as an opposition for many years.
If WP is to suffer the same fate as SDP, to me that means it'll start to lose credibility as an opposition through a series of events. Let's look at what has happened so far. Starting with YSL's alleged adultery, but WP sacked him. Then before BE, Sajeev resigned and caused a stir with accusations of racism. Then PLG turned up without party knowledge as spare tyre. All seems to cast doubts on WP's internal cohesion. Not forgeting the resignation of Eric earlier (and one other Malay chap whose name I can't recall right now). And then Png was attacked throughout the campaign on his integrity and a leaked confidential document topped it off. If we believe in conspiracies, then we should sense that these series of events might not be random but carefully orchestrated.
The biggest question is: by who? GD care to enlighten us? (Hope I'm making sense to you, GD sir)