I don't know that a "formal" retirement announcement is needed. Harris's plans for running a team in B.C. in 2024 were announced months ago. That said, he certainly deserves an opportunity (if he wants it) to publicly say farewell. Assuming (as I do) that Muamba also retires, he will likely be offered get a chance to announce it at some sort of media availability. Maybe Harris will join him there if that happens.