Yeah I don't really know what to say about Cole...and apparently neither does Cole. He literally had zero lines in the trailer, even when the topic was him, it was nothing but people talking ABOUT him, around him. So....that's a bit worrisome. I wonder if the actor is just not very good, and every time he opens his mouth reflects this? So they just edited around it for the trailer? *shrugs*
As to "Why isn't X in the movie?" I mean the roster, even with just the first game or 2 of characters, is too large for a film to really have much coverage for. So I don't really mind them leaving some people out. I mean they left Jax out of MK 1 movie, but he's in it this time. I mean you KNOW they are hoping this will be a franchise, so they can bring in the other characters in later films. Honestly Cage was never a character I enjoyed much in the games (movie Johnny Cage, I loved him to death, he was great), so I don't really mind him not being in it.
As to Johnny specifically not being sellable today? I don't think so, I mean media celebrities are huge now, on every level. I could maybe see them changing him to...I dunno, an MMA fighter who is also a live streamer, or some kind of online personality, who is also a badass fighter? I mean it's not like there aren't fighting movies out there, with actors famous for being in fighting movies (The Rock and Jason Statham come immediately to mind, and they are hugely popular right now). So yeah I don't see it being a "he doesn't translate well in today's always online culture", quite the opposite. What I hope is that they just couldn't think of a way to work him into the narrative they have made, with the whole Street Fighter meets CSI angle they're going with Sonya and Jax. Which frankly, I'm fine with that. I'd rather they saved him for a situation where it makes sense to have him in it, than just shoehorning him in to appease the fans, even if it clashes with the storyline.
*edit*
Holy shit I use the phrase "I mean" a lot when I'm typing.