I've come to realise something...
Like many of you, I came to FF through the OG. I loved it and still do. Over the years, we got the compilation, most of which I ignored and separated in my head from the original game. For Nomura, Nojima, and Kitase, though...that separation never took place. This remake project was never going to be VII all over again, because that time has passed -- now it's the VII Universe, like the MCU, and this universe informs everything, even the original game. So of course Zack is going to be involved, considering his immense popularity after Crisis Core...of course Reno is going to have more playfulness, as in Advent Children...of course Sephiroth is going to pop up a million times, because that's all he has done for years, even in a darn Mickey Mouse game.
It's tme to put on compilation goggles when looking at remake, and our theories will be all the better for it. With compilation goggles on, suddenly Zack seems far more important and close to essential to this story. Minimising him doesn't make sense.