The Malaysian police claim the pilot is the "prime suspect" because he made no "social or professional future plans".
If that single observation makes one a "prime suspect" in an aircraft hijacking/loss - then 10,000 other pilots around the world, are also "prime suspects" for future hijackings/aircraft losses.
In the very unlikely scenario that your aircraft crashes AND you have a completely clean diary from that date forward, then yes I'm afraid you almost certainly will become a posthumous suspect.
I quite understand that on a professional pilots' forum, there is going to be considerable opposition to the idea that an apparently distinguished professional pilot might choose to down his plane. And I note this forum is deeply distrustful of journalism, which can be sensationalist and inaccurate in its reporting of civil aviation.
Yet pilot suicide has happened before (Egyptair 990) so it is not surprising that it is a major avenue of inquiry for MH370. In this case, it is 'the butler did it' scenario. So the moderators who deleted all the posts following yesterday's Sunday Times article are, it seems to me, in the same state of denial as the Egyptians who continue to blame a CIA conspiracy or mechanical failure for the demise of Egyptair 990.
The aftermath of air crashes is frequently highly emotional and politicised so there are some, like Egyptair 990 or Itavia 870, where for these reasons the truth is never accepted by the airline's home country. This is wrong but perfectly understandable. It's just a shame that Pprune moderators seem to be guided by exactly the same emotions.