I don't think that this is going to happen. You are right that the morality of combat logging took a big hit due to better authority response. But it's pure speculation that this leads to proper punishment by FDEV. They could've punished combat loggers before since they already said it's considered an exploit and the best argument against 'griefers' is still Solo mode, not better authority response. And we still have the problem that we don't know if someone pulled the plug or if someone has connectivity issues. People will argue that it's a strange coincidence when someones connection always drops when he is in combat, but what happened to the benefit of the doubt? Allegedly FDEV has means to distinguish deliberate and unintentional combat logging, I just don't believe it until someone explains how this should work.
Even if we see punishment against combat loggers at some point I don't think that they are going to punish the trader that pulls the plug once or twice a week (I am very sure that you'll need to do this repeatedly before FDEV takes action against you), they will punish those that initiate combat and leave the game as soon as it gets dangerous. Due to the nature of the game and the size of the galaxy it's unlikely that a trader combat loggs repeatedly in a short span of time.
That's why I don't believe that a longer timer will improve piracy, if anything it will lead to more combat logging and I doubt that FDEV is able to change anything about that.
So what can YOU do about combat logging? Simple: Create a private group. Invite all the people that want to play with you. Kick everyone who leaves the game during combat, regardless of pulling the plug, logging to menu or connectivity issues. Promote it on the forums. Call everyone that doesn't join your group a coward. If you are clever you'll find a way to reward people that play with you. This is the only solution I can think off - everything else will not work.