I have a theory that one of the cockblocks in Gillovny’s relationship is The X Files itself. They seemed fully together until the rumours of S11 started (recall D’s bday tweet to G in 2016). IMO she was pressured to do it, possibly gave up other opportunities (personal and professional) for this franchise, and will continue to do so until Fox pulls the plug. D&G would never come out as long as X Files is still a thing.. it’s not either of their styles.

I think they would never come out until XF is happening, I agree with that. But I don’t think it has any impact on the status of their relationship, or at least any negative impact. She doesn’t have to do anything she doesn’t want to even if Fox puts pressure on her. Actually, I really don’t think they’re putting pressure on her, I think they’re just adding more zeros to her contract until she says yes. If that’s what you call pressure, I wanna be pressured! 
To me, XF and Gillovny are two different things well separated, and at maximum, XF is just their excuse to spend months of togetherness. The rest of their relationship isn’t connected to the show at all. If it’s working, it’s working with or without the show and if it’s not working anymore, it’s because something went down between them.