Follow the minimum and then unfollow them soon after the sign-up process is complete.
Since anyone signing up for Twitter may
- be expected to want to try their services but
- not be familiar with them
enforcing a small sample selection during the (guided) sign up process seems quite reasonable to me.
Then, once the installation process is compete the user can immediately proceed with testing the system out without being left to struggle independently, in what may be unfamiliar software, finding how to follow people.
So there is some reason to expect that bypassing these requirements, if even possible, may not be straightforward.