Well, it's here.
The most important thing is to keep the current size. Removing the button and bezels, the screen can grow to around 8.5". That is plenty.
All it really needs is a CPU and camera upgrade. Pencil would be nice, but personally I don't care about that. Give the mini 5 the specs of an iPhone 8 Plus and it will be great.
It looks like the specs of an XR and XS instead. And yes to pencil support, yes to updated cameras but still with the same form factor, bezels and all. Better display technology as well.
I'm very ok with this. I won't be upgrading soon, but my AppleCare+ is up on my Mini 4 next month, and I would have been pissed if I had to buy 2015's technology to keep the same form factor if something happened to my current one.
(Also hopeful that cases, accessories, etc., for the Mini 5 will fit the Mini 4, so I can get a new case if mine wears out - it seems to be getting close.)