@atomicpoet I'll probably block this myself if I see it in my feed. That said, the content on its own doesn't necessarily violate many policies to the point where it belongs on a global list.
Of course, if the accounts on the instance actually starts spamming then I'll immediately change my mind.
That said, I think you're eventually going to be right, since there is zero profit in posting on just the timeline of an instance that contains nothing but marketing. You need reach, which will drive these people to spam. However, that spam is what should get them on the lists, not the mere fact that they have a feed full of marketing.