I have been getting this message consistently in my applications that use the Photos framework (import Photos). It does not seem to impact functionality of the apps. I see it when running on the Xcode simulator and when running on actual devices and in both production Xcode and Xcode Beta 6.
Just for fun I took a look at the runtime console log for a Photos app (PhotosDisplay) I designed while running on an actual device (iPhone X iOS 13.7).
The iOS system program accountsd logs “Unentitled access by client PhotoDisplay…”
And then PhotoDisplay logs “Error returned from daemon: Error Domain=com.apple.accounts Code=7”
While this does not answer what exactly is going on it does give some context that it is pretty deep in the framework and probably not something we can control.