It's not that the dynamic, post variant, method is necessarily a bad thing, it's just that most users don't navigate or reference threads that way. The most typical reason it's seen is coming from the "updates/alerts", and perhaps hard to replicate and explain.
I see this mostly as a bit disconcerting, and self-referencing in the top slot could perhaps be better selected as the user may initially follow that, and when they come back try the second, and so on. That could be frustrated if the list keeps changing/moving.
I'd agree that taking to a user to a specific post within a thread is probably ideal, the user interface really doesn't communicate that nuance.
From an analytical sense I'd probably like to see the whole thread, with the salient content marked-up or high-lighted, but that's probably a big ask.
