You guys are putting far too much stock into such a baseless rumor. There’ve been no official reports and none of the movie news sites I follow have made a peep about it.
That’s exactely why I said that making a younger Han Solo (or at least casting an actor who is 10 years younger than Ford was in 77) for his standalone movie makes it doubtful that they’d use that actor for a cameo in Rogue One.
But if they really want it, there are plenty of ways to have a Solo cameo. All they need is having solo not knowing about the Death Star.