I'm running a 2560 build of 7.7 on a similar machine (FFCX) and I do have that option. On that page it has: Check SD reads; P-Stop Control; P-Stop Inverted; and Serial I/O. Build is 7.7 r01591.
Pretty sure that the filament runout detectors respect the default sense of p-stops and go active-low to initiate a pause state. The inverted option should only be necessary if your sensor and/or p-stops are wired to go active-high in the event of a commanded pause.