Seems like Apple is indeed doing an M2 Max chip with 12 cores ..
Benchmarks of Apple's upcoming M2 Max CPU which would feature 12 cores have leaked out and shows up to 20% improvement over M1 Max.
wccftech.com
M1 Max 8+2 1785 / 12785
If we are to assume the efficiency cores perform at about ~1/3 performance cores, then the performance is equivalent to 8.67 cores or 1475 points per performance core.
If M1 Max were extrapolated to 10+2, it would be 1785 / 15735.
If M1 Max were extrapolated to 8+4, it would be 1785 / 13768.
M2 Max single-core here is 1889. Extrapolating single-core points it would be 1561 points per performance core.
M2 Max 8+4 extrapolation is 1889 / 14570.
M2 Max 10+2 extrapolation is 1880 / 16652.
The score we got is 1889 / 14586.
I know this is almost the mathematical equivalent to handwaving, but if this Geekbench 5 M2 Max score is legit, that would imply an 8+4 configuration (not the 10+2 I had favoured).
Meanwhile, my iMac Core i5-7600 is 1119 / 3808 and my Mac mini M1 is 1768 / 7812.