Just curious, why does Rick only release a few tour dates up front and then more later? Maybe he always did this, but I never noticed until recently. I don't think it's because tours fill since I noticed dates being added while original tours were still available. I want to book a trip but the exact date I would like isn't offered. I'm thinking should I wait but risk my tour filling...
They’ve always done this.
The tour conditions allow you to transfer to another tour (details here: https://www.ricksteves.com/tours/tour-conditions ). You could always sign up for a tour you are willing to take and then request to transfer if a better date opens up.