Don't use it, ever.
The reason is two fold. First, there's no way to know whether or not your biometrics being collected by Apple or some other company. There's no way to know whether some other program or app (either on your PC or on your phone) can get access to your biometrics. Even if the EULA (End User License Agreement, you know that thing where you clicked "Yes, I have read and agree to these conditions" even though you didn't read it and don't understand it) says that data won't be collected, there's no way to tell if the company will change the EULA in the future (and almost certainly would "grandfather" your agreement).
In short, you don't know who will get your biometrics, and you probably can't know. Heck, I can't know, and this is sort of my business.
Second, one thing about passwords that everyone has always agreed upon (and your fingerprint is basically your password, right?) is that passwords should be changed regularly. Good luck with changing your fingerprint. People also agree that you shouldn't use the same password on multiple devices or computers. Once again, good luck about picking another finger print.
When you combine these two issues, there's a non-zero risk that you will be giving person or persons unknown the data that they will need to be able to impersonate you in the future. This is an incredibly bad idea.
It's one thing for Apple to know by iTunes playlist history. It's something entirely different for them to be able to be me. Do I think they would? Probably not (probably). Do I think that this would be considered a valuable data asset by them? Damn straight. Companies go out of business all the time, and this information would be of considerable interest to those attending the Chapter Seven liquidation.
So don't do it.