My guess is julia or who ever plays Christine just calls out on matinees. So if you want to see julia don't go to a matinee, but if you want to see her understudy go to a matinee. I don't get why they wouldn't have an alternate or at least a listed one for the tour. Isn't the role still as demanding as it is on Broadway? Christine probably has to sing more on tour, because they don't use a voice over when they go to the layer.
My father (AIDS)
My sister (AIDS)
My uncle and my cousin and her best friend (AIDS, AIDS, AIDS)
The gays and the straights
And the white and the spades