At least the scan date is a real piece of data that could be useful. This seems like it would cause more harm than good by polluting the data with nonsense, unless the added dates are clearly labeled as estimates
The way to increase the accuracy is to add a birth year to face tagging so each photo has an anchor that the AI uses -- "This photo has joe, joe is born in 1950" and then it will look at how old joe is and if joe looks like 10 years old, it knows the photo is around 1960.
Just sign up for an account and you can date 50 photos for free.
The images are yours in your account. I think there are better ways to get images to train a specific AI model than to make a small app for users to upload a few...