Many of us w/TOS tend have fairly normal MRI's. This may point to more soft tissue causes vs an obvious cause showing on the imaging.

A normal MRI does help to rule out c spine & other obvious bony anomalies that could be a cause of pain/symptoms. like extra cervical rib or large bony structures.

"mild prominence of the C7 transverse processes"
does that mean on both sides?
are your sx on both sides?
I kind of wish they would say the sizes of what you have compared to what a "normal" might be...

Quite a few in the past have had blocks to help with diagnosing & locating the area of concern.