Like I said, if the 32-bit stuff is getting used, that's an argument not remove the support.
> And being able to get away with less RAM also improves battery life because keeping RAM refreshed uses energy - again a bigger factor on mobile.
Memory allocation exists purely at the software level. The hardware doesn't understand whether a particular region has been allocated or not; the only difference between an allocated page and an unallocated one is that the former appears in the OS's VMM data structure as allocated (i.e. it's just more bits in memory). The power consumption of RAM scales with the total cells installed, not with how much the OS has decided is "in use".