[GeoffR]

I just noticed that some pre-orders do show the book's format on the Kobo website, while others don't.

I don't know why this is, but maybe in some cases the book has already been uploaded by the publisher and is just waiting for release date, while with others the publisher hasn't yet uploaded the book and so the format is unknown.

Edit: Also it seems pre-orders which show the book's format also have a preview option available, but those lacking the format information don't.