No, it's a kilozip, like kilometer (= 1024 meters). A gigazip (not gibizip) would be 1'073'741'824 zips (1024^3 = 2^30).

Also it should be Gzip, not gzip, although it's not ambiguous since the reciprocal prefix is nano-, and in general there are no 2^-X0 prefixes that start with g- like there is for Mega-/milli-.