Does OneDrive Keep Photo Dates?
OneDrive keeps the date inside the photo. The Date Taken column in Explorer can still look empty for other reasons.
OneDrive uploads and downloads the file unchanged, so the photo's own date survives the round trip. Its gallery view sorts by that date, which is why the web view often looks right.
In Explorer, files that are online-only show limited details until they are downloaded. An empty Date Taken column can simply mean the file is not on the disk yet. Right-click and choose Always keep on this device to check properly.
If the column is still empty once the file is local, the photo genuinely has no date. Takeout JSON Metadata Fixer puts one in. It runs on your own computer and is free for your first 500 photos.