I think all these comments here are kinda talking past each other.

It all depends on the amount of duplication and the complexity of the abstraction. Like you said, no generic advice is possible that clearly separates it into "abstract here" and "duplicatehere".

In your example it sounds like we aren't talking about 2-3 places where duplicate code existed that just needed to be refactored into separate units. It sounds more like a complete disregard for abstraction to move on quickly.

If you see duplicate code and have a good understanding how to solve that then it's totally a good thing. The real problem comes in if you add abstractions without knowing wether they will hold up. And this is where the blogpost comes in. In my opinion 2 duplicates are fine, at 3 you should start thinking or implementing an abstraction if you have a good understanding of the code and usecases.