Did you actually look at the sources and verify any of that?
Source (4) is a generic guide to sysupgrade, it has nothing to do with WED/WO, doesn't even mention it.
Regarding the definitions:
WED: The term stems from the original implementation which is part of MT7622 and offloads forwarding from Ethernet to Wireless, ie. WiFi TX is offloaded only. Hence packets received on Ethernet are dispatched to Wireless, hence the name. More recent versions (MT7986, MT7981 and later SoC) do support also taking care of the traffic received on the Wireless interface.
WO: Wireless Offload Firmware In order to perform WED on recent SoCs a dedicated offloading firmware is required. It is called WO firmware.
So to be clear: WED means offloading traffic forwarding from/to Wireless. It works with the existing flow-offloading aka. HWNAT engine of MediaTek SoCs, just like for forwarding Ethernet traffic. Newer SoCs need firmware to perform WED, and that is called WO firmware. Because WED is now bidirectional, MediaTek started to use the more generic term WO instead of WED, which suggests a unidirectional nature as it has been the case on MT7622. Today, the two terms (WED and WO) mean the same feature.
Please forget all the well-sounding but rather meaningless stuff that chatbot has told you. Thank you for at least having clearly marked that post to be the result of a Copilot chat.