WT44 I am preparing my hat for eating but doubt whether in the end I will have to.
If any were going to leave then waiting until Dec7th for the final tranche of Bonus would not make the difference between staying and going!!
When you go for these jobs you have to take them when offered or not at all, certainly that is the SIA Chinese way which I doubt varies in other Chinese Cultures,one does not usually have the luxury of choosing a starting date to suit your own personal convenience.
Also the very 25yr+ SIA Captains you refer to, as they are well set up financially as you suggest can well afford to sit back and stay at SIA, also I suspect that they don't want to have to lose face and join as new boys in a new foreign airline.
Still time will tell. I have flown with many F/O's who talk about going to Emirates but have yet to see any go even as far as the interview stage.