Wanted to provide an update here.
First of all, if you are running into bugs (like all your photos have the same date) please reach out to support. If you’re on mobile, you can shake your device, if you’re on the web, you can use the settings cog.
As for the ability to change metadata on photos, that’s not something we currently have on the immediate roadmap.Mario Dabelić commented
I just uploaded a few hundred files - MP4s and JPGs and not happy with result.
Below are source files, their information, and the corresponding OneDrive information after I uploaded them.