Maybe we will start seeing other teams draft a QB 3 years before they need to, but probably not.
I've always believed a new QB needs at least two years sitting, and learning, so they don't lose their confidence. It isn't always the most talented QB who is the best one on the field. It's quite often the smartest one, who knows how to move the team, despite not being as good as the other guy. A prime example is Bart Starr. He was a fairly accurate passer, but most of all, he knew how to insure the Packers were all on the same page, play after play. It's called "leadership," and it isn't something the new kid on the block automatically can step in and offer. It takes time, and patience, getting there.
The problem, in today's game, is that if you don't win it all this year as a coach, you're in serious danger of being fired. So, they throw the kids to the wolves, and it's either sink or swim, from day one. Because of it, way too many fail miserably. When the self confidence, almost bordering on arrogance, is gone, so is that little margin of difference between them being a really good QB, and one who isn't going to be around too long.