The drivers for wireless network adapters are already included, the script just downloads firmware files for some (very) old Intel and Broadcom chips which are under especially restrictive licenses. If you have basically any hardware from the past 10+ years, it will work (or not) without running the script as the firmware needed for those are already included.
(Specifically, the broadcomwifi..., iprowifi2100, and iprowifi2200 drivers need the firmware that script provides. If you have any other hardware, e.g. atheroswifi, iprowifi4965, etc., you don’t need the script.)