They're not known as Sids' "Pirates" for nothing.
It's not personal, it's only business. In the past, when layoffs became a possibility, the company appealed to its incumbent aircrew to "volunteer" for "SLS" - Special Leave - in order to "save jobs". In return, it was agreed that the company would address a number of outstanding industrial issues.
They haven't addressed ANY issues that were on the agreement. 4 years and counting.
I can confidently predict that if CX asks the aircrew again for "special" dispensations, the answer will be a resounding "NO". We will see layoffs. Yes, the 19 Adelaide guys should and will fight for date of joining - or the street it will be.
This is unprecedented for CX, but more common than you would think - in the region, SQ, JAL and others have all had redundancies in the past.