Thank you for reaching out to the Zoom Developer Forum. Great question! My understanding is that clause is saying that you can’t use the APIs to attempt to create a product that competes with or replaces the differentiating features and functionality of Zoom.
When it comes to creating a registration form, I wouldn’t say this is a feature of Zoom. Instead, it’s a requisite of creating an account. This is especially true if you are looking to simplify the sign-up process for users under your account. Recreating a feature would be something like using the Zoom chat API to create your own chat application that is entirely separate from Zoom and intends to compete with Zoom chat.
That being said, depending on your use-case, you may find benefit from directing users to the Zoom log in page so that they can register or log in using our website. I mention this because it removes one more piece of the puzzle that you have to implement and maintain.
I hope that helps! Let me know if you have any questions.