What do you think about the new Z6 III features? The pre-release capture looks really interesting. I use Live Photos on my iPhone every so often to reselect the key photo. It doesn’t look like there’s an option to create gifs in camera from the pre-release capture photos. But I bet third party apps should be available.
What are you doing with your photos? 24MP is more than enough for almost any format, except maybe the largest of prints. But you’d need to get good framing in camera, without as much room to crop.
All indications are that Nikon won’t be making a Z7iii, so if you want more pixels I’d go Z8. They’re on sale for $500 off right now. Also if you run DX glass, or set to crop mode, you’ll get 20MP files, so fairly close to your d500 right now.
I (almost) never print, the advantage of the extra pixels would be the ability to crop significantly and still end with usable shots. Once I go full frame the plan would be to sell the old kit. A couple of my lenses indeed come from the d7000 days! The 50mm/1.8 IIRC.