Will an EU company be allowed to manage US data?
In compliance of US laws and regulations, of course. For example, by following US data privacy laws... oh, right, there's no such thing, my bad.
As employees who wish to retain our employment contracts, we have no opt-out option.
Anonymous denunciation to the geographically relevant data protection agency. Opt-out is mandatory. Data may only be collected for a legitimate purpose that must be explicitly justified. Every database holding personal informations must be declared to the data protection agency so it can check for compliance.
FORTUNE'S FUN FACTS TO KNOW AND TELL: A firefly is not a fly, but a beetle.