You may see Haarberg in a wildcat type role or on a trick play with 2 QBs, but it doesn't seem likely at all that he moves away from a QB role on anything even approaching a semi-permanent basis. He's very, very likely the #2 QB either listed straight up or in a -OR- with Danny.
Gramstad is not a thing. Fans/media want it to be a thing, but the coaches approach to the QB room has been deliberate and consistent since these two freshman arrived. That did not change when Gramstad arived. It hasn't changed as we quickly approach the announcement of the starting QB and the initial public depth chart. If they were going to make Gramstad a thing, it would have happened a long time ago when they could have eased their way into it. If they did it now, it would be an absolute disaster. You can't sell yourself as a coach to your players on loyalty and transparency and then pull something so against your messaging at the last minute. You'd lose not only the QB room, you'd lose the locker room. It simply will not happen unless injuries or similar inability to play happens to those other 3 QBs.
In this day and age when guys leave early due to transfer or the draft, you have to play your best players and worry about redshirts later. Nelson is more valuable to this program as a 3 year guy that gets drafted high than he is as a 4y and 4g guy. For Nebraska to get more of these top guys to do more than just visit, they need to show they can both win games and put blue chip talent into the league.