Currently, 12GB is a rather standard amount of RAM in smartphones. It is a matter of time when 16GB will become the standard among the most powerful phones on the market. Already on the occasion of premiere of the last flagships from Xiaomi, journalists assumed that company could decide to jump in this aspect to 16GB of RAM. However, this didn't happen. Such a jump will probably be made after the release of the upcoming flagship devices from the Chinese manufacturer.
Earlier information indicated that the latest phone from the Mi Mix series or the Mi 10 Pro model would receive 16GB of RAM, but this wasn't true. The latest reports indicate that the upcoming flagship from Xiaomi will have this amount of RAM. However, we don't know at the moment exactly from which series this phone will be, hence we have to wait for confirmed information on this subject from the manufacturer itself.