For comparing GPU sizes, found this online tool,
link:
https://comparesizes.com/comparison/Gpu-compare-size-comparison/1575224670224#/
Just add in the GPU dimensions (usually in mm) and GPU name and you can easily compare the dimension differences between several GPUs.
Are there any rumors of decreased size or weight?
As long as the GPU chip increases in productivity, it also increases in heat production IF Nvidia/Radeon like to keep the GPU die same size. Also, GPU has other components as well that need active cooling, like VRAM.
Due to that, better performing GPUs need bigger cooler and in turn, GPU is bigger and weighs more.
Single- and dual-slot GPUs doesn't need GPU support since those usually aren't heavy enough, like RTX 4060 or GTX 1660 Ti (latter is what i have).
Triple- and quad-slot GPUs do need GPU support, else-ways the GPU sag either brakes the GPU PCB near the PCI-E slot, or PCI-E slot itself splits apart.
Or new ways of connecting to the mb so there isn't GPU sag etc.?
There is. That is called vertical mounting and is done by vertical bracket + riser cable.
Looks like so:
Vertical GPU mount depends on your PC case.
Some PC cases support vertical mount off the bat, e.g Phanteks Enthoo Pro 2 TG:
https://phanteks.com/Enthoo-Pro2-TemperedGlass.html
Many PC cases can support 3rd party vertical mount, e.g Cablemod vertical mount:
https://store.cablemod.com/product/cablemod-vertical-pci-e-bracket-2-x-displayport-black/ (Image above is showing Cablemod vertical mounting kit.)
And for some cases, no vertical GPU can be installed, since even aftermarket vertical mounts doesn't fit. In this situation, replace PC case which does support vertical GPU mounting.