If the guy you met had so much seniority he can probably chose to stay at Martinair Cargo, and proceed with his Martinair career. Some less senior people (bottom of the list, i believe 67 men/women) can switch to KLM and start a career there. Indeed they get no seniority BUT there is no loss of salary, and they still have a job.
There have been extensive discussions in our labour union, and after long talks this plan was accepted by both pilot groups.