It was Mary. Mary is a very important character in the Christmas story. She was visited by the angel Gabriel who informed her that she would give birth to the Son of God. Mary's faith and obedience are often emphasized in the story. She is an integral part of the events that led to the birth of Jesus, which is the essence of the Christmas celebration.
Well, it could be argued either way. Sometimes, even with the same character, there can be nuances in the performance or the way the story is presented that might make it feel different. So, it's not a straightforward yes or no.
It is indeed the original cast. Their return adds a nostalgic touch and authenticity to the Christmas special. The familiar faces make the viewing experience all the more special.