It's sad that this started WAY back just 6, 7 weeks after the iPhone 6 / 6Plus came out. This was brought up back in Nov, 2014
https://discussions.apple.com/thread/6686660?start=15&tstart=0 Now for these people, I'm sure an instant replacement was issued - I hope. This issue doesn't seem to be happening with the 6S/6S Plus right now.
"In the iPhone 6s/6s Plus, Apple moved the susceptible Touch IC chips off the logic board and onto the display assembly, presumably sheltering them from most of the flexing forces the logic board is subjected to."
So..my assumption Apple knew of the flaw well over a year ago - so they moved that Touch IC.

Grr, this is sort of connected to the old "Bendgate." Those who are not having the problem right now..it's possible we can avoid this by using a protective case - I guess the stronger, the better. And do not place your iPhone 6/6+ in your back pocket. Basically try not to bend it! Luckily I haven't had this issue (Knock on wood...
I've had battery problems though in my 6+)
Well, easier said than done I guess...if I do get this gray bar issue, it would be silly to get it fixed - averaging $300-350 for the fix. I would probably just bite the bullet and upgrade...even though I am
trying to keep this current phone until Sept 2017.