The FRA inspection is necessary before a track can be brought back out of "Out of Service" status. With light traffic levels and a willingness to run at 10 MPH, the track can be brought just up to the level of "Exempt", where it can probably be operated just fine for quite a while (depending on overall conditions like bridges and drainage). Good-tie densities, rail condition, and cross-level issues are very leniant on "Exempt" status. It probably wouldn't take much to even get the line into Class 1 status. Obviously, any part of the line that there is any chance of passenger service is going to need a much higher Class designation.
About the only thing that an FRA inspection can do as far as NOT re-opening the line is if a bridge inspection reveals anything that makes it impassible by itself. If any Contractor worth having on the property has been working on track items and passing over the line at all, there's little or no chance of bad track conditions ALONE causing the line to not be re-opened.