What do you think happened to the other characters caught by the thought police?
What happened to Parsons? He wasn't guilty of much unorthodoxy. He may have been happier in a labour camp than at home with his hateful kids. Why would the Party waste him when he could still be useful?
Winstons assumes Symes was vapourised, but was he? Symes was not unorthodox, just indiscreet. Why would they vapourise Symes and not Winston? O'Brien presumably interrogated him. Symes, no doubt, denounced Winston, not that that would have made much difference.
There was a poet named Ampleforth, who thinks he was arrested for not being able to bring himself to use an inadequate rhyme for 'God' in a poem. He must have been mentioned early in volume 1, but I don't remember him. He doesn't sound like he's guilty of very much.
The party is so cynical they may well decide to execute Parsons, Symes and Ampleforth while keeping alive Winston because he is an interesting case.
I wonder whether the party hadn't decided to have a bit of a clear out at the Ministry of Truth. Instead of making staff redundant, the party arrests them, interrogates them and either sends them to a labour camp or executes them.
Julia sounds like she's going to live. The party knew all about her, but I doubt they would have brought her in except for Winston. They may have got around to her eventually, but she wasn't a priority. Julia's not very political. She mostly wants sex and intimacy.