For both my PC & my phone, even with this recent revision when the input/edit post panel is minimized, it is still visible, just like it was a week ago. It’s appears as full-width stripe across the bottom of the window / screen in a contrasting color containing the reply curved arrow icon and the thread title at far left, and a close X icon at far right.
As noted, in my previous post, that is true on my Win11 PC with Edge, and on my Android with Chrome. I use the Discourse Classic theme.
I wonder what device, browser, and theme you’re using that the minimize function disappears the whole post.
I do know that historically if you open a fresh post, type nothing, then minimize it, the empty draft post is simple closed and deleted. But once it has at least one keystroke in it, it behaves as I’ve described above.
For me. YMMV of course and I’d like to learn more about your setup & symptoms.