True depth camera disabled

This Support article is specific to seeing a 'disabled' Face ID alert, and explains what to do when you see that notice. --> If an alert says Face ID has been disabled on your iPhone or iPad Pro - Apple Support

Unless a software update solves the problem you may need to have Apple take a look at your device. Use this link to set up an appointment —> Genius Bar Reservation and Apple Support Options - Apple

For your question regarding Apple policy, you will have to ask Apple: Refer to this document for ways to contact Apple ➞ Choose your country or region - Official Apple Support

Select your country (also look for "other" regions), then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service by telephone ➞ Contact Apple for support and service - Apple Support

Oh, I also don't know if it is a widespread problem with certain phones. Sure, we see posts here about this but sometimes it is accompanied by a, "I dropped my phone in the toilet," text which may explain why there's a problem. As for certain models, well, Face ID is only available on certain models. Frankly an iPhone is a piece of complex but still sensitive electronics. Most people don't post a long history of iPhone use and care so we don't know why the feature doesn't work but there could be a good reason because of accident or careless behavior. You are welcome to keep an eye on Apple's service bulletins if there is a manufacturing error resulting in a problem Apple Service Programs - Apple Support