Disagree. I've enabled fingerprint which was off by default. I want to be able to use it instead of my password, regardless of whether I've just started the app or not. It's my preferred method of authentication, and I accept the risk that someone might acquire my fingerprint - if someone has managed to do so, and has access to my phone, I have bigger problems. But I am not an international spy, nor, to my knowledge, are any interested in my reddit password.
If this feature becomes reality, I would really hope that it's a configurable option, because the current behavior is exactly what I need and want.