- Is shooting Winston inevitable because the Party does it to everybody, or is it because Winston still holds some deep seeded thoughts?
I do not think that Winston's inevitable end will come as a result of him having these thoughts. The thoughts Winston has are of a hatred of the Party still. Even after his days of rehabilitation in the Ministry of Love, where he is starting to believe that 2+2 can be 5 and freedom is slavery, he still holds this thought. His mind has become corrupted by the Party, but he is hoping he can maintain his heart.
In his heart is where he can still have love for Julia and everything that they did in their time together. He can also house his true feelings of Big Brother. To me, this leads down the same road he went on during the whole book thus far. He starts to act on these thoughts: buying the diary, speaking to proles, renting the room, engaging in a relationship with Julia, and ultimately back at the Ministry of Love because the Party knows everything at all times. As mentioned before, this might be why Winston has had the dream about meeting O'Brien in the place where there is no darkness (aka the Ministry of Love), it has happened to him before possibly.
I think ultimately the Party let's the "patients" live their lives after the Ministry of Love to see if they have really turned over their new leaf. They won't kill them right away, because they would have killed them while they have not truly believed in Big Brother, the Party, INGSOC, double think, etc. There is still the potential of them being seen as martyrs. Once people are completely sold on all there principles, then they are eligible to get vaporized. This was the mistake O'Brien said the Russians and Nazis made. The people obeyed, but deep down they still hated the people that had power over them