SIA doesn't have any pilots that aren't ; Singaporean , Malaysian or foreigners with
PR.
Retrenchments would be from all of thee groups but, probably more foreigners with
PR.
Expatriates were terminated many years ago and I don't believe that they have employed DECs since.
SIA is a career airline and a few expatriates from the 70s and 80s took out
PR but, none did so in recent times because the salary was so much better as an expatriate.
Those foreigners who have
PR would have come through the cadet program or SilkAir and worked on local terms from the start.
To them
PR would make sense but, not to expatriates.