It wouldn’t do much at all, because the current canonical version(s) is(are) the only one(s) that anyone would accept. Any older versions would be rejected as attacks on Christianity. There were a couple of “Secret Gospel of Mark” versions circulating in classical and post-classical times that were branded heretical, and wound up in the Vatican archives, the rest of the copies burned. Not sure the archive copies have survived to this day.
Hard to say. In the days of the internet they couldn’t be as effectively suppressed.
They would eventually have a shot at being part of the canon.