Yes, technically it is an armv8 chip however, when running in 32bit mode, it reports as an armv7 processor. Armv8 is a 64 bit processor, and arm processors running in 64 bit mode will show up as aarch64 in the kernel.
Becuase the zero2W has only 512k RAM, I would run it in 32bit mode, as 32 bit has a smaller memory footprint.