So it looks like at the latest the journal was submitted in November and could take 9 months which is August. Looks like no significant news or clinical update most likely until then so wait we will!
233 was chosen because that was the minimum needed to have adequate statistical power for OS. Going beyond that means greater power, which is not at all a bad thing.
233 happens to be the 70% mark of the 331 patients. (Just as 244 was 70% of the 348 patients)
I noticed when Dr Bosch last spoke at conference, that he was starting to mention "a minimum of 233" .... so that is when I started to get an inkling that they were considering going beyond the 233 event threshold. I think I posted something to that effect back then.
While you are basically correct the need for IO therapies to demonstrate long tail benefits has become the driving factor in such trials, particularly with the first approval of a therapy.