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.Marek commented
Is there any update on this ? It's been almost a year since the idea was submitted. I have 100+ GBs of photos backed up in onedrive and a number of them need the dates to be corrected. I'm slowly reaching my quota so I'll need to upgrade to 1TB plan. If there are no changes in functionality then I'll guess I have to move everything to Google....