To me this sounds like a way to rationalize a decision not to do Scrum. That's their decision, Scrum isn't for everyone and it's not the only successful way to be agile (XP, Kanban etc). I just don't think the above argument is a valid one and shouldn't be used to sway someone in favour of another agile methodology.
Scrum doesn't need to explicitly outline these practices because it's a framework that can be used outside of software development as well as within. When done well it implements all of the practices and values, whereas some of the technical practices might not be right for your development environment.
I'm not saying that Scrum practitioners shouldn't use the above technical practices I just don't think that they need to be mandated (I personally recommend TDD, CI etc for my teams where appropriate).
Also because Scrum is a framework it gives us the flexibility to use any current or emerging practices, technical or otherwise. In fact most scrum practitioners I've spoken to encourage people to actively seek out and experiment with other ideas provided that they don't conflict with the Agile Manifesto or Scrum values. This was also mentioned in a Scrum Alliance update by Mike Cohn where he states that Scrum is not enough.
Finally, practices such as TDD and CI have successfully migrated out of XP and have taken a life of their own. I see more technical and non-technical practices doing that in the near future. This will allow skilled practitioners to mix and match based on the environment.
If you agree or disagree please let me know. I'd love feedback.