Several factors play into why someone's novel take off outside of just posting your link.
Work Ethnic: They have a scheduled update system they follow. Their readers know when they'll update, and they generally post announcements if they need to miss one.
Other Platforms: Tapas Forums is not the only place to engage with other people -- if they're published on other platforms and engaging elsewhere, they will generally bring readership from those places.
X Novel: This isn't their first novel. They've been working on other stuff and continuously posting. They have experience.
Someone doesn't get staff-picked just because they posted in one of these threads. There's a lot of behind the scenes we don't see that goes into play. Again, Tapas Forums is small compared to the site, which houses 70,000+ comic and novels. We're not putting a dent into the actual data at hand here. And a lot of the staff picks -- you don't see them on the Forums. But that doesn't mean they're not engaging in other communities: they're just not engaging here.
If those threads help you, that's fine. But for sustainability, it's helps to do more than just drop a link.