Update to myself (and others that read this)
I called AT&T Premier and asked. I was told the following:
"We are being told if you currently have 3G unlimited on the iPad, you will be moved over to LTE unlimited."
Other questions I asked:
"Will the unlimited plans be restricted to 3G and not be able to utilize LTE?" - "No."
"Is there any data caps or throttling on the iPad unlimited as there are with the iPhone unlimited?" - "I have not seen any throttling or data caps on the iPad, only on the iPhone".
This was one person's answer. Mileage may vary.