No, that doesn't make any sense. There's no way that a procurement manager or a sales VP would have sufficient power or safety to topple the bourgeoisie. That's a ridiculous sentiment. As we all know, the workers could just topple the bourgeoisie too and they haven't, does that make them lapdogs and class traitors?

Middle management are not the supervisors, by definition. Supervisors of front line staff are excluded from the definition of middle management. Without supervising workers, middle management cannot be "the police" because they are not interacting with front line staff directly and cannot monitor them. Middle management primarily works with abstract collections of information, generally responding to price signals, and provide the information management tasks required for organizations to make decisions.

And they are not bourgeois soothsayers because middle management doesn't talk to investors, bankers, creditors, and politicians. That's upper management and explicitly excluded from middle management.

So no, middle management are not police and are not soothsayers. They are well paid members of the working class who are given a larger cut of the surplus in exchange for operating the bureaucracy of capitalism instead of the machine rooms of capitalism. They can be as much class traitors as individual laborers can be class traitors. But the role/work in and of itself isn't inherently class betrayal.