They're from an even more obscure place, actually:
https://www.bellingcat.com/news/2023/04/09/from-discord-to-4chan-the-improbable-journey-of-a-us-defence-leak/
However, the WowMao server may still not be the original source of these documents.
Bellingcat spoke to members of a separate Discord community who claimed that other images had been posted earlier on yet another, since deleted, server often called “Thug Shaker Central” but which also had several other names at different times. Image files shown to Bellingcat detailed a further document in the same style and formatting of those posted in the WowMao server that was dated to January 13.
Yet given the images shared were screengrabs and not a link to the original server post which has been taken down, it is not possible to independently verify their authenticity. The content of these documents beyond the date and classification was also blurred out when shown to Bellingcat.
The Thug Shaker Central server was originally named after its original founder, one member of the server with the username “Vakhi” told Bellingcat. Server administrator duties then passed through various users before a new member took on the responsibility and it went through one of many name changes. Vakhi did not want to name this person but said they were the original source of the leaked documents. According to Vakhi, and two other users who spoke to Bellingcat but declined to be identified by their usernames, the files that were leaked onto WowMao are only the “tip of the iceberg” compared to the quantity of documents posted onto Thug Shaker Central.
There are no traces left of this server outside of testimony from these users, and scattered references to its existence on 4chan. Bellingcat is therefore unable to independently verify all of the information shared by these users, including the aforementioned January document or if the other uploader described as the source of the leak was indeed the original source.
However, Bellingcat was able to confirm that Vakhi and the other users who spoke to Bellingcat, as well as another who shared documents on the WowMao server, were part of the Thug Shaker server given that they shared member lists with Bellingcat which matched in key details.
Their accounts of the server’s general nature also independently coincided. The name of the Thug Shaker server frequently changed, sometimes to that of a racial slur, and had around 20 active users making up a tight-knit community, members said. Posts and channel listings show that the server’s users were interested in video games, music, Orthodox Christianity, and fandom for the popular YouTuber “Oxide”.
This server was not especially geopolitical in nature, although its users had a staunchly conservative stance on several issues, members told Bellingcat. Racial slurs and racist memes were shared widely.
Bellingcat contacted Discord to ask about the existence of the Thug Shaker Central, WowMao and Minecraft Earth Map servers, as well as whether Discord had any knowledge that “Top Secret” documents were apparently being shared there