Languages sometimes have different sort order, even when they use the same script. So I could see using ML to detect the language, in order to select the proper sort order.

Including merging in name in different languages and scripts... And trying to figure out whether the user really wanted an English interface when they set up the phone, or just had prior bad experience with poor localizations...

Isn't the language a setting in the OS somewhere? I don't think you need any ML to figure out what language a user's phone is currently using.