Looking at Micron (who probably tickd the box on price to make this happen), they can do 16Gb modules. So that may well happen. However the power aspect as already indicated from the 4Gb to 8Gb, considerations will prove more interesting.
Biggest gain though is more focus upon 64bit, which goes hand in hand with that extra memory.
Interesting as Samsung developed a 8GB LPDDR4 memory chip back in 2013 - https://news.samsung.com/global/samsung-develops-industrys-f...
Looking at Micron (who probably tickd the box on price to make this happen), they can do 16Gb modules. So that may well happen. However the power aspect as already indicated from the 4Gb to 8Gb, considerations will prove more interesting.
Biggest gain though is more focus upon 64bit, which goes hand in hand with that extra memory.