Even when you run the fans at over 7000RPM to drop the CPU temp by 20 degrees C, the M2 MacBook Pro doesn't run any faster per Max Tech's testing so I don't believe it is correct to say that the M2 thermally throttles.
As with Max Tech's testing of the entire M1 family, it doesn't looks like Apple allows any M series SoC to draw maximum power (as measured by wattage) to run the clock speed at the maximum rated speed, but instead keeps it a few hundred MHz below that maximum both single and multi core.
This seems to be to allow the SoC to run with either no fans or at the minimum speed possible for as long as possible.