Blizzard have added another clarification on the new boosting-related rules, specifically relating to advertising the boost runs.
Boost Advertising (Source)
That would not be fine.
To provide more clarity for those who have been wondering where the lines are drawn in this new policy, we’d like to summarize that part of it.
Advertising for gameplay activities should be done by a WoW player-character who intends to participate in the gameplay activities. This means there should be no cross-realm advertising, and there should be no advertising from non-participating players.
And as before, the only place that advertising a “for gold” activity is allowed is the Trade channel. Advertising in any other chat channel or the Group Finder makes the player subject to actions against their account.
Source: News Latest Topics https://www.icy-veins.com/forums/topic/64002-boost-advertisment-rules-clarification/