The minute they said "We'll show up for work on condition because an Israel we don't control doesn't deserve to be defended properly" then they should have all been fired.

They broke the deal in the sense that they were trained based on the historic statistic assumption of how many voluntary reservists would continue showing up. Sure, many wouldn't continue, but when dealing in large numbers it could be assumed based on historic patterns how many would Quitting as a group was unexpected. stick around.
If a soldier declared right from the begining of service that they would never serve a day more than required I suspect that that individual would never have received pilot training.

The pilots in particular have a real issue with the judicial reform as proposed. Many air force reserve pilots work as commercial pilots on civilian life, regularly traveling outside of Israel. Because of their actions whilst on active duty, there have been various attempts over the years to have them arrested ant brought to the Hague for war crimes - i.e., the deaths of civilians during arial bombings.

The main protection they have is that ICC rules preclude the ICC asserting jurisdiction where the home country's judicial system is seen as robust and impartial, such that any investigation/trial in such home judicial system. Israel's courts were seen as meeting this standard, thereby protecting the pilots whilst they were abroad. The concern with the reform is that it's possible that the ICC will no longer consider Israeli courts independent - leaving these pilots at risk of arrest and prosecution should they leave Israel.