that the team has all of the skills necessary to produce the product.
It is a statement of the skills necessary.Being focused on the vision for the product is a necessary requirement of how they work
Some people have confused cross-functional with every one on the team can do
anything that is needed. The cross-functional team must be able to produce
releasable product. Typically, non-cross-functional teams don't do that, but only do one step in a process that ships. For example, there could be analysis teams, coding teams, test teams, and so on... as opposed to a cross-functional development team, which goes from idea to shippable product.