No, they don’t show up. I know how that works.
It’s not that uncommon for me to click through to topics that have been deleted. It has happened to me enough times that I’ve figured out when it happens and what exactly happens and how to get out of that state. (Force quitting the app is the way I normally get out of this state, since it’s the first way I figured out.) But yeah, it’s an edge case.
I don’t know where those controls are generated. I assumed it was in the app, not Discourse itself. If so, it seems odd to me that the app suddenly doesn’t show necessary navigation controls depending on which page you’re on. Up to you all whether it’s worth fixing or not. I just know that when it happens it always takes me a bit to figure out what’s going on. (Scroll up and down and wait for the controls, but they never show up. Then, in the past, force quit thinking the app is just not working.) Now that I finally figured out what causes it, I thought I’d report it.
Cheers.