I’m not familiar with that particular story, but it’s worth noting that there is a nationwide union for franchise restaurant workers called NGG. They negotiate standard wages with the franchise restaurant association BdS which all the big names adhere to (McDonald’s, Burger King, KFC, but also, for example, Starbucks). Your story sounds like it’s about a “Betriebsrat”, which represents workers within a specific workplace, complementary to wider unions.