That is not standard in the U.S.; only assistant professor positions are typically tenure track.
The new Berlin law does not say anything about a "tenure decision" that has anything to do with academic excellence. In practice this will mean that almost everyone on such positions will be tenured.
The Berlin universities will probably react by drastically reducing the number of postdocs hired on such positions as otherwise it is too costly.
The new law simply says that postdocs can only be hired on a tenure track. This seems to be uncommon in Germany, but standard in the US, I guess.