Personal Take on GDDR6+:
It's probably for Navi III, but there's a decent chance Intel could use it for Battlemage too, if availability is there.
At best, it'll be 5% more efficient than GDDR6X per bit, which itself is more efficient than GDDR6.
I see no world in which GDDR6+-24000 consumes less energy than GDDR6X-21000.
GDDR6+ might reach HBM2-levels of efficiency, but at those data rates, that's still a lot of power.