An alert is hardly the place to list detailed code warnings. I think the prompts are enough to have one open their app in Xcode and review the specific depreciation warnings.
They’re not. Pretty much every developer I’ve talked to has no idea what this warning means or what they should be doing in response to this. All of them are smart people who are longtime Mac developers. There are a bunch of ways to improve this: you could tell people to look in Console for logs, or name the deprecated API being used. What Apple did instead is they decided to shame apps by name but not tell them what they did wrong, and do so in a way that is quite broken because the warnings don’t even line up with deprecated API usage.
Looking at the Console is precisely what I thought of, at least coming from Windows, where I'd be looking at the Event Viewer to know more about such a message. Does the Console show more information?
Will have to check but I think I remember looking at the code to generate these and didn’t spot anything but the alert enabled by default.