Now it seems to be official, Cloud will get a redesign in the upcoming Final Fantasy VII Remake which will be released in episodes, starting hopefully from 2018. From January 22. until February 28th 2018 there is a exhibition called 別れの物語展 in the Mori Arts Center in Roppongi Hills, Tokyo (Homepage) and there was an official talk with developers of the game. During the talk they showed changes to the character Cloud, which are not official released in public yet, so that attendants are not allowed to official talk/reveal what changes exactly are made.
It seems that the new design is official accepted by Tetsuya Nomura, who is the official character designer of the original Final Fantasy VII and is said, that it is the closest version to the original character design. (Japanese source)
So it is not clear yet how much and what get changed on the current character design. It could be a complete redesign, but also just small changes to the outfit or other things.
For everyone who hasn't seen the official E3 trailer from 2015, here it is once again.
And here is a nice comparison video between the original game and the E3 trailer footage.
