Last time I heard someone answer the jury discussion question was in S3, from Kelly Goldsmith.The jury has never been sequestered from each other. They have hung out between TC's. In Outback, Africa, and Marquesas, EPM segregated non-jury fron jury.
Kelly said they were under strict instructions not to talk about any aspect of the game or try to learn info about what was going on after they left, outside of what they learned at TC. She didn't find out that Brandon helped boot her until it was over, for instance, even though the two of them were having daily picnics.
It was my understanding that the S2 jury had too much discussion, so they clamped down on S3. Whether the rule changed subsequently, I don't know. However, the analogy would be similar to a sequestered jury that cannot discuss the case with each other--only in this case they can't discuss it until after they cast their vote.
Re: what they learn at TC... we see only a fraction. They may spend an hour or more on Q&A: we see what the editors select; as the jurors base their vote on much more interaction than what we see, we really do not know what info they have or what outbursts or mean comments may have been de-selected for our non-benefit as spoilers.
Even after the Final TC, they are not supposed to tell each other how they voted or it's a violation of contract that could cost them their prize money. It really is possible that no one but the inmost production circle knows for sure who won the vote.
In the past, some of the comments from jurors would not have given away their ultimate vote.
"If we knew today what we knew yesterday, we couldn't give it away"--Aimee Mann