They were using LFG which is why they got dinged.
OP here is the related Support article on advertising and services.
'https://us.support.blizzard.com/en/help/article/187406
Can I sell Mythic+ boosting services?
* A player is selling a mount code in the General chat
- There is a player spamming a gold selling website in Trade chat
Accounts that are used for the primary purpose of advertising will be closed.
Selling in-game items and services such as carries or boosting for real money is not allowed. Organizations who offer boosting, matchmaking, escrow, or other non-traditional services (including those offered for gold) are prohibited, especially those operated across multiple realms.
Individuals and guilds are allowed to sell items, crafted items, profession services, etc. for gold but can only advertise these trades in-game through the Trade chat channel.
Individuals and guilds are allowed to offer GDKP* runs and boosting services for gold, as well as request gold tips for assistance in raiding, completing dungeons, or PvP activities. Any and all advertisement must occur in the Services chat channel**. The advertisement must be done by the WoW player-character who intends to participate in the gameplay activity. This means there should be no cross-realm advertising, and there should be no advertising from non-participating players.
*GDKP is not allowed in Anniversary, Hardcore, and Season of Discovery realms.
**You can type /join Services or /leave Services in any major city to join or leave the Services chat channel.
Reporting
To report a player for inappropriate advertisement, use the right-click option. You will not receive a direct response, but we take all reports very seriously.
[/quote]
This thread. Then the person tried rules lawyer which just plain got it locked.
They seemed to ignore the key line in the Support article.
Any and all advertisement must occur in the Services chat channel.