I would bet the industry will invent something to replace it anyway, even if there's no good reason for the change. Or maybe there will be some fundamental leap making 80 Gbps as irrelevant as 9600 bps are today.
Side note, there's some really really cheap fiber optic DisplayPort cables out there. They work, they're whatever length you want, mine were ~$0.60/foot. My monitors are 4k60 & 2k170; all resolutions run great. I feel like we're not too far off from fiber maybe happening for real.
