Make of it what you will, but I thought this was a very interesting reply from their Facebook page, which is slightly different from the rest...
Any chance Darren Browns ghost train will be open on the 24th of this month in traveling from Southampton and brought tickets especially for this? And as its my birthday too really don't want to be let down
Thorpe Park wrote:
We do not have a confirmed opening date yet. If it is not open on the day of your visit you can visit guest services and they will be able to help!
Of course the reply is virtually the same, but it is interesting that the mention Guest Services.