FP+ for Princess Meets question

[PSofiasMama]

I have reserved a FP+ to meet Cinderella on April 30th. After talking with my daughter decided to try and change it to meeting Rapunzel. I was unable to do so and eventually discovered that for everyday of our trip the Princess Meets (both Cinderella and Rapunzel) are not available at all. They are greyed out and instead of being able to select them it says standby list available.
Does anyone know why this might be?

Thank in advance!

 

[krist315]

Wondering if it has anything to do with the press event at MK