CPt
Correct for the old gen aircraft, but the 777er is a bit different.
Older aircraft, or should I say, those with smaller engines, are limited to 25% thrust reduction for T/O and so with the max clmb debate being 20%, this normally resulted in a pwr decrease at thrust reduction alt.
However, the ER derate on T/O is up to 40%, so with a 20% derated Clmb, a pwr increase results.
Not always, but at anything but a near limiting T/O
Also, To save fuel, some operators are removing the Clmb derate at anything over MLW, so pwr increases to full Clmb.