IMHO when the settlement happens, negotiated or not, those that were hanging on might not like the new environment.
Sure the over 60's might not amount to much but most are Captains and for every retiring Captain leaves a compounding number of F/O and even more so S/O vacancies.
With numbers starting to get tight now watch the good 'ol QF stuff it up again and be left short!
Impossible to think but historically a proven thing unfortunately.