No, the Minions didn't work for Hitler, Minions & Monster director confirms.

Theory Briefing

• A viral fan theory argues the Minions' compulsion to serve history's greatest villains logically puts Hitler on their résumé.
• With a new Minions movie in theaters, the director was asked directly and confirmed the answer is no.
• The theory hinges on the franchise's own internal logic — if the Minions follow evil, the timeline has an uncomfortable gap.
• The director's denial now sits against a fan base that built the case from the movies' own rules.