To be fair, that Swiss decision was completely reasonable. The systems they were scrapping were old, unmaintained and not produced anymore. It made no sense to invest time and resource to teach a lot of ukrainian air defenders in order to then launch a small limited amount of missiles and then scrap the system anyway.
I think by swiss ammo the parent comment refered to the 35mm ammo for the Gepard Air Defence System owned by the German Armed Forces that was produced by Rheinmetal (but in Switzerland) that had to remain in Germany.
AFAIK the Gepards are still in use in Ukraine, but Rheinmetal is now producing the ammo in Germany rather than using the former Oerlikon-Facilities in Switzerland.