https://www.techpowerup.com/298560/nvidia-geforce-rtx-4080-comes-in-12gb-and-16gb-variants
 
NVIDIA's upcoming GeForce RTX 4080 "Ada," a successor to the RTX 3080 "Ampere," reportedly comes in two distinct variants based on memory size, memory bus width, and possibly even core-configuration. MEGAsizeGPU reports that they have seen two reference designs for the RTX 4080, one with 12 GB of memory and a 10-layer PCB, and the other with 16 GB of memory and a 12-layer PCB. Increasing numbers of PCB layers enable greater density of wiring around the ASIC. At debut, the flagship product from NVIDIA is expected to be the RTX 4090, with its 24 GB memory size, and 14-layer PCB. Apparently, the 12 GB and 16 GB variants of the RTX 4080 feature vastly different PCB designs.

We've known from past attempts at memory-based variants, such as the GTX 1060 (3 GB vs. 6 GB), or the more recent RTX 3080 (10 GB vs. 12 GB), that NVIDIA turns to other levers to differentiate variants, such as core-configuration (numbers of available CUDA cores), and the same is highly likely with the RTX 4080. The RTX 4080 12 GB, RTX 4080 16 GB, and the RTX 4090, could be NVIDIA's answers to AMD's RDNA3-based successors of the RX 6800, RX 6800 XT, and RX 6950 XT, respectively.
 
Looks like NVIDIA wants to offer 16GB of memory as an option to compete against AMD's next gen GPUs. 

Miguell
so can we assume... 16GB is the new base Vram from now on?
 
i mean.. if people truly want sweet eye candy texture details at 4K and even 8K then 12GB may not be enough!
right?

How can you even possibly infer that "16GB is the new base VRAM" from a report that conflicts 12GB and 16GB variants? The reality is that most people (it's not even close actually) do not use a 4K monitor for their PC, most people (the vast majority) still use a 1080p monitor for their PC. Hell, the latest Steam survey only had 4K primary monitor resolution at 2.5% usage. You know what was higher than that by almost 3 times as much? The old outdated 1366x768 resolution at 6.2% usage. Also we are in no real danger of being 8K ready to game, even on next gen GPUs. They would need to increase their performance output by at least a factor of 3 to even start to be viable at 8K resolution with high graphical settings. We just aren't there yet and probably won't be for at least another 2 or 3 generations at the earliest. 
 
The point I'm trying to make is that no, 16GB VRAM will not be the baseline for VRAM not for this generation. Just because a high end video card has 16GB of VRAM does not make that the new baseline. The standard will more than likely continue to be 8GB with entry level starting at 4 and 6GB VRAM. 

Not a fan of a single product having different memory bus widths. That'll have impact upon performance numbers although it'll be named the same.