Let us think of this phone from Motorola's perspective.
A) What is the point of having 2.75GB (your guess, not mine) of RAM?
B) Referring to point A, why increase the cost of parts for the phone for RAM that won't be required for several cycles of smartphones
C) Increased part costs = less profit
This tweet, as fake as it is, is referring to onboard storage. Plus, why would he take the time to clarify that the RAM is onboard? There isn't going to be a port where you can slap in a chip and get more RAM. Despite the significantly faster speeds of RAM compared to any consumer solid state storage device, you aren't going to be storing "everything I capture or record" in it. You don't need raw speed for that, and you certainly wouldn't have enough capacity.