What would make sense would be a deal where Finger Lakes takes over the service,
Why would it make any sense for FGLK to run to Corning, when the cars are brought to them at Geneva now? From a railfan perspective it might be cool to think of a railroad going new and different places. From a business point of view, you would be increasing operating costs, increasing exposure to potential liabilities such as grade crossing incidents, and many other unattractive possibilities. For what? The cars are already delivered to them. Would it make sense for FGLK to run over CSX to get their cars at Selkirk, rather than having CSX deliver to them at Solvay?
While FGLK has proved adept at growing business, there is not really much potential for new traffic on the line. If fracking is allowed, if some gas storage place were to open up, if the coal fired power plant re-opened, if NS decided to dispose of the line and the alternative was abandonment...if...if...if.... - then maybe it would make sense. If not, it makes no sense to take over miles and miles of track just for the sake of doing so.
I'm not trying to give you a hard time. I'm just trying to figure out why NS would want to get rid of a branchline that generates revenue.
Disclaimer - I have heard nothing to indicate NS wants to get rid of the line, and the following is general in nature and does NOT address this situation re FGLK and NS. But in many cases, railroads seem to apply standards other than normal business practice to their decision making. This was especially true in the time from the 1960s to....1990's maybe?
It can't be denied that at one time the railroads had too many people doing unneeded jobs, and had unproductive branch lines. It thus became the yardstick by which managers were measured, to see how much they could reduce costs in one or two areas - such as the number of crews, or how much overtime was worked. Never mind that those crews may have been needed, or the overtime helped get some work done. It was smoke and mirrors and only the specific parameters were measured. So the focus was not "does that line generate revenue", it was "how many crews can I cut if we get rid of that line."
I believe this mentality has largely been eliminated, at least hopefully so. Again I'm not saying this has any connection to NS/FGLK Corning, but the fact that a given line generates revenue has not always been relevant to how it is viewed.