With OverDrive MARC Express, you'll receive two MARC records for preorder titles: an initial record when you purchase the title, and another when the title reaches its street date. The second MARC record overwrites the original, and its "Titles for delivery date:" page in Marketplace is intentionally left blank.
You can download these overwrite files to see the complete MARC Express record.
To see which titles are included in an overwrite delivery without downloading it, you can use the Purchase orders report (under Insights > Popular reports). Under "Order description," look for "Preorder added_" and the date of the delivery.