Hi Antonio,
It's an ongoing debate whether it's good to put repo information into POMs or not, see e.g. [1]. The major problem is that users of such a pom.xml as dependency will get that repo pulled into their own build, which might not be what they want.
Now I guess there won't be many people using the TCK as dependency, but I still think it's saver to leave the repo info out of the POM and have users add it to their settings.xml. With the BV reference implementation we provide an examplary settings.xml which can be used for building: mvn clean install -s settings-example.xml. I've created a ticket for the TCK to do the same [2].
Thanks again for your feedback,
--Gunnar