I don't really get the whole sleep thing. Currently in iOS 13 I find "bedtime" to just be a silly feature that assumes you go to bed and wake up at the same time every day, and it assumes that you will magically go to sleep when it tells you to. Not even your mom can make you do that. As for wind down, just put down your phone when you want to wind down. Relying on your phone to suggest you do more things on your phone in order to wind down is just silly. Turn on do not disturb, stop calls and notification from appearing, and turn it off when my alarm goes off. Also the "good morning" thing is silly, I always laugh when I get the good morning screen when I've been at work for 3 hours... or when I don't get it when I wake up late. It just assumes that morning is at 8 am and that's all. I'd say morning is just whenever you wake up.
Also I just can't imagine anyone getting a notification to go to bed and then going like "Oh wow, I almost forgot to go to bed! Well good thing my phone reminded me!"
The only thing that's good about the bedtime app is the non-annoying ringtones that aren't annoying even when being woken up by the same tone for a whole year. That's good sound engineering right there. Except you can't use those ringtones in the regular alarm app, which is the only one that actually makes any sense... I don't get why.
Personally, here's my ideal wake-up app that no one has ever invented yet: it starts a very very silent alarm 1 hour before you need to wake up that gets gradually louder over the course of an hour. It would prepare your brain for waking up before you actually have to. Oh and the sound is just white noise or something very non intrusive.