Roy Williams and his wife Wanda. By TOM SHANAHAN The Twitter world can move on to another subject. Royal family speculation has longer legs than theories Williams concocted a scheme behind his latest donation to his alma mater. North Carolina coach Roy Williams didn’t donate $3 million on Monday as his retirement swan song entering the 2021 basketball post-season. Nor was it way to win favor with athletic director Bubba Cunningham to remain coaching the Tar Heels another…