So Samsung today has announced its 10nm class 8-gigabit (Gb) LPDDR5 DRAM. I'm wondering if it would be possible to increase the size of the RAM using the new DRAM.
DDR5 would require more power, meaning portable devices that require bigger batteries and that would produce more waste heat. Not a good choice for phones and tablets.
The important part here is the LP which stands for Low Power. The "DDR4/DDR5/etc" part denotes the generation of memory. A higher number usually indicates better speeds, higher density, etc.
Stacked anything is problematic in a high power device like a laptop processor. Actually it's somewhat problematic already in smart devices also, because these draw enough power nowadays to become quite hot as well.
Without further technical innovations like fluid microchannel cooling or whatever the boffins might come up with - or simply something that vastly lowers power consumption - I wouldn't expect stacked memory in laptops or desktops.