A temporary "other" Superman for a sales gimmick, I guess. Kind of Jean Paul Valley and Dick Grayson and even Jim Gordon and (I heard rumors) Luke Fox Batman-ish. It's old, it's tired, it's boring, and no one thinks it is going to be the real new status quo. So some will find it entertaining while is lasts, but likely more will just be "wake me when it's over." Though maybe we will get yet another universe reboot to end it.
If true, this is more of Jon's identity being torn away to make him a literal Superman stand-in. So sad. I would say it's actual Superman-hood being stolen from Superman, but I can't take it seriously enough as a long-term change to even care about that, because it is so not going to last. I suppose a "Jon isn't Clark" resolution could come from it, but I doubt it would happen without one character or the other being trashed.
This just seems too tailor-made to rile both fanbases (that have some overlap) - those who feel like Jon's individuality is being stripped away and those who feel like Clark's key achievements are being stripped away.