I think it's the right time for this move.
Yes some people wore black face thinking it was 'tradition', 'disguise' etc. And had no intention of offending anyone.
But have you ever watched the Baccup Coconut Dancers?

Many teams have changed their paint, either colours or patterns. The discussion has gone on and now what everyone knew had to happen has been made official. Similar to the timing of the ruling about letting in women. Too soon and it is a shock, but dancers have had time to get used to it.

PC or simply good manners.