I agree but i wouldnt say that 2Gb ram is common right now even though it is getting more common.Then you have as much knowledge as the developers, or maybe more. I think you're being way too optimistic.
Currently the mobile version of the game running 1.2.4 uses a LOT less RAM than it should because the game assets are being streamed only as needed. It was a design compromise to drastically lower the system requirements, but made parts of the game not work correctly compared to PC. The new 1.3 patch will run using the same logic as the PS4/XB1 version, where the entire game is loaded and updated in real time. So it will be running on different hardware than the PS4/XB1 version, but will be using the same coding. Having the entire game constantly running, even the parts of the map you aren't in, is going to require a HUGE amount of RAM compared to the current implementation on mobile.
Mobile devices with 2 GB or more of ram are becoming very common. I think the new implementation of the game on mobile will need at least that much. Otherwise I think they would need to cut back on features for the mobile version like the previous developer did. I'm not sure it's worth their time to continue to support mobile devices with any less than that if it means they will have to cut back the experience in a meaningful way.