Yup, mentioned that already in a few previous posts. I bet Apple does it next year. The key to this planned obsolescence is to never give your customers everything. Save something for the future so they keep coming back. It's like video game arcade machine designers. Some made impossible in certain levels for players to keep putting quarters in the machine.
Reason why I believe a jet white is coming is because I remember being attracted to the black Xiaomi Mi 5 Pro at first. Then I saw all the smudges on both black models (glass or ceramic). I saw the white model and was more impressed by it. Also, remember Nexus 4 and 5 had white variants but came months later if I recall. I said it before that the key to making a front white display is to put enough black borders around the screen so the white won't be distracting. All white front iPhones lack that.
White, silver, and gray resist smudges the best.
Black or dark color are prone to smudges the best.
LG nailed it with the white front V20.
Before LG, it was HTC that nailed it with the One M7.
Enough black borders to see contrast when watching a video. Sometimes a white model front shows the design lines better. White + silver + black around the display look great together. We wouldn't see much of that One M7 speaker grills if it were matte black and would be prone to smudges.
Unfortunately, the iPhone 6 series have hideous rear lines. That's why the black/jet black iPhone 7 series became so sexy for many people because it also hid them. The jet black looks the most uniformed. Nomore dual tones where the color of the front and back are different.