In my estimate, those guidelines are for cases where staff actually looks at a project. It might help decide an edge case, to show you put in effort.
In my estimate the indexing is not a quality test. They try to keep bad actors away. Think malware, scams and bad joke projects or bot uploads.
My issue with the official faq is, that it is outdated and therefore overly optimistic. It would be more accurate if they exchanged days with weeks for their estimates. The current wording makes people think they did something wrong, then they contact support and still nothing happens for "days", so they worry and worry. The project is in limbo and no one tells them what is going on. The truth, in my opinion, is that staff just has a huge backlog of things to do. You do not have to pay 100 $ upfront like on Steam, so there is not really a budget for checking out every release. Automatics can only do so much, and staff does get bombared with a lot of bad things. Actually I guess the recent rise of spam comments mean, that uploading bad projects has gotten harder and the bad agents try different approaches.
Your traffic generation is one of the few things that are said to help speed up the process. It makes sense. If the project really is a bad one and it has traffic, it shoud get removed earlier, so staff has incentive to check it out earlier. Also, doing your own marketing and not relying on being indexed is the recommended course of action by Itch. You will see this stance in some threads about similar topics.