It runs normally without a head attached, so they must not be doing this yet. The architecture authenticates the body to the brush, which is the reverse of what you would do to lock out brushes. (A third party brush can get the password from the body and say "yup, that's definitely the password" and then the body thinks it's genuine. Meanwhile, a third-party body could use genuine brushes because a brush can't mechanically make itself not work. So there just isn't any lock-in here.)

The main feature this seems to be used for is to put the body into "whitening" mode if you use a whitening brush.