Unless the airline is planning to park aircraft, hence reduce capacity significantly, there is no need to quickly reduce the pilot numbers.
Asian airlines don't usually downsize their fleet size significantly but usually fine tune route frequency etc to reduce any losses.
If the airline does decide to phase out a particular aircraft type from the fleet then expats probably wouldn't get a transfer onto another aircraft type but find their services terminated as the last of the type departs.
Airline management may decide to terminate pilots ( using the notice periods stated in contracts as previously mentioned ) that have been 'problematic' but normal attrition and the option not to renew expiring contracts will normally provide adequate control of numbers.