Directly from the source! Here is the Superstition Iris Garden's reply to Jane's (Janielouy) question:
"NO, you do not automatically get the “pre-catalog” lists via e-mail unless you have either: (1) made a “pre-catalog” order this year 2016 or (2) unless you specifically ask for those lists—otherwise, you have to wait until you get your catalog, which hits the mail, usually around Feb 1. If you placed an iris order this year 2016, then you will receive the catalog for 2017 automatically.
Those add/dropped lists will be e-mailed on December 12. We haven’t decided when we will start accepting “pre-catalog” orders yet, it is normally around January 1, but we started December 15 last year. That info will probably be announced on our Facebook page—or who knows, we may have that date listed when we e-mail the lists on December 12."
Hope this helps!