Preview calls are manual dials, so can't be Auto-answer by definition. Callbacks are not any different. Currently, callbacks are not dialed by the dialer, but presented as manual dials to the agent like a preview dial. If the auto-answer is required, I would suggest a web service that delays insert into a Predictive/Progressive campaign. That would allow the delay like a callback and the auto-answer like you are wanting.
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Robert Wakefield-Carl
Avtex Solutions, LLC
Contact Center Innovation Architect
robertwc@avtex.comhttps://www.Avtex.comhttps://RobertWC.Blogspot.com------------------------------