Keep dreaming, and you will never face reality.
The truth is that yes, Yamaha did release an update that included more ram (which was actually a process of "unlocking" part of the physical ram that was already available on the keyboard for other uses, such as audiostyles) and other system improvements.
But, (yes, there is a but) the Yamaha Genos is the current flagship keyboard.
As far as we know, it's the only arranger keyboard Yamaha has done that to, and that's no guarantee that it will continue to do so with other mid-range keyboards.
I'm sorry but your question doesn't make sense, and no, there is no information on that.
Instead of speculating on that, you better take advantage of your time enjoying your keyboard AS IS.
Wait for more updates to fix bugs, but to wait for more ram etc I think it's completely illogical.
Sorry.