It's not tokenism, it's business. Any organisation can hire out the park. If the Salvation Army wanted to hire it, they could, and I doubt there would be much of an issue.
It would be tokenism if Alton Towers actively went out and said 'oh, let's have an all-black day'. If a legitimate organisation representing African Carribeans hires the park, it's just business. You're a pretty sharp fellow, I'm sure you can appreciate the distinction.