As reported on the Wikimedia Commons Village Pump https://commons.wikimedia.org/wiki/Commons:Village_pump#The_upload_script_no_longer_takes_the_date_given_as_the_original_photograph_date
User are reporting that UploadWizard pre-populates the data field with the file last modification date, not the file creation date.
(I have not reproduced this myself, just filing this as tracker)