I can see how this would be really useful to better explain technical content and make long form content more engaging.
Launch HNs (and also job ads) for YC startups are special mechanisms that get special front page treatment. This is in the FAQ: https://news.ycombinator.com/newsfaq.html#yc. In that sense, but only in that sense, submissions are not treated equally. We do those things so HN gives something back to YC in exchange for funding it. That's important for a balance of giving and taking, and for HN's long-term future. I believe the bulk of the community understands this and is ok with it.
The important thing to understand is that these are specific, clear exceptions to HN's general practices. Other than that (plus orange usernames for YC alums), there are no such exceptions. In particular, what you describe here is absolutely not ok:
> sometimes come pre-loaded with canned comments that all show up at once.
We tell all HN users, including all YC founders, never to do that. Not only that, but I tell YC founders that it's the fastest way for them to get flagged and flamed by this community, and that there will be little we can do to salvage their thread if it happens. Basically I try my best to terrorize them about this. You'll notice that it's the only bold text in the Launch HN instructions: https://news.ycombinator.com/yli.html. It's also one of the few things that appear both in the FAQ (https://news.ycombinator.com/newsfaq.html: "Can I ask people to comment on my submission?") and in the site guidelines (https://news.ycombinator.com/newsguidelines.html: "Don't solicit upvotes, comments, or submissions"). The rules are clear and they're the same for everybody*.
> There is one on the front page right now that I suspect is up to something like this
What is the link? Even when non-YC startups or projects do this, I often tell them not to and explain why it's not in their interest.
* That doesn't mean we automatically ban people for breaking them; there's a gradient of punishment. A lot of the time people have no idea that they're breaking rules or local conventions. That's different from hardened manipulators trying to game the site, people buying upvotes or comments from spammers (<-- do not! that will get you banned!), and so on.
It's true that booster comments aren't helpful in the end, but people often post them without the slightest idea that they're doing anything wrong. They don't deserve to be piled on. Also, vsarathy didn't upvote this submission; that's not the mark of a typical manipulator. The benefit of the doubt would have gone a long way here!