New "Midwest Class" seat maps now loaded in YX booking engine, but even with refundable fare requested, only the standard (aft section of cabin) seating is available for seat selection.

I would think that Signature seating would be available for advance selection with refundable tickets priced at 2 or 3 times that of a non-refundable fare.

Currently, if a flight is booked thru an agency or online with a booking site other than YX, Signature seating is available in advance with the purchase of a Business fare (usually more than refundable fare). Sites such as Travelocity, which use Sabre, no longer show Business class (C) fares available for YX's new schedule. At this time, seat maps are not showing, either, on their site.

How does a customer book Signature seating in advance for the new Midwest Class and what is the premium?