As Steve mentions, we are now living in a brave new world of political correctness where what was once considered good and wholesome is now determined to be offensive, and subjects once reserved for the saltiest of bar rooms abound for the eyes of the innocent.
While the prospects of seeing Charlie Chan on major TV/cable networks may not be likely anytime soon, there is still some hope that smaller networks or stations (that can only gain viewers in such a venture) my do so. Recently, I had an email dialog with a gentleman from a minor religious network that shows an occasional classic movie as well as "The Lone Ranger" and "Lassie" TV shows. Evidently, they will be showing Mr. Moto and Mr. Wong movies in the near future, and, if this happens, could Charlie Chan be far behind? They seemed to be open to the idea, at least.