Tucky to Cincinnati makes sense beyond the Washington connection. It is much closer to home for him. They have a new, young and exciting coach. However, it is not all roses. He will have to sit a year and is changing positions. Despite the Fickell excitement, he is also leaving a Power 5 team for a mid-major.
BC and Addazio could have made his release conditional and "blocked" Cincinnati, but they did not. Fickell shares an Urban Meyer connection with Addazio and BC doesn't want to make enemies in such a traditionally strong recruiting area for us in Cincinnati. Tucky and the Bearcats also played it the right way. In the article there is no mention of Al Washington nor his prior relationship with Tucky.
I don't imagine any other current BC kids are going to leave to reunite with Washington. But other kids will leave for various reasons when they are not happy at BC. That is why all coaches need to sell BC first. It is not about the assistant, nor Addazio, nor playing time. It is about playing and going to school at BC. That is all the coach can guarantee. If the kid buys that first, the other unpredictable stuff becomes less important.