I thought the reason people were in black face for that was because of chimney soot, not because he was actually meant to be black.
ETA I had a listen to the audio report:
It's quite interesting and presents the various arguments. Songs refer to Pete being "as black as soot". It's contentious. If it is racism, tradition isn't or shouldn't be an excuse. On the other hand should Pete be excluded from history? Sounds like the UN will keep pushing for revision due to perceived racial stereotypes being depicted in the songs and the blacking up.
I think Mary Poppins is safe on that count although the sweeps Cockney accent was pretty bad.