No that isn’t a misprint. The ARM was nearly two orders of magnitude more cycle efficient than the MSP430 and AVR. Thus my claim that the modulus operator can be very inefficient is true for some architectures – but not all.
The first thing a real embedded guru would do is look at the assembly listing. My guess is that ARM actually provides operations for integer division and modulus, while for AVR they're implemented as low-level gcc library routines.