Workplace democracy would most likely and most broadly refer to all employees of a company having a say in how the company is run. Either by voting on policies and changes, or by electing people to various executive/representative roles, much the same way that current Western democracies work.
An example of the janitor voting on where the surgeon makes a cut makes about as much sense as us voting on where the president flies in his helicopter. At best, it doesn’t pass the make sense test, and at worst is a bad faith interpretation of what people mean when they say “workplace democracy”