If you make another support ticket, our support team can help you understand specifically what led to the disabled project and how you can prevent that in the future.
Since you mentioned a link shortener, I suspect some of the links your users have been making have been reported and found to be malicious. Even if your previous ban was treated as a false positive, continued reports of abusive content will still be processed.
When you operate as a platform with user generated content (allowing users to link to malicious sites that get hosted under your domain) you need a process for responding to reports and taking down abusive content, just like the process Vercel has to follow.
This is something all hosting platforms and link shorteners need to abide by or they can be legally liable for the criminal websites they allow on their service
One popular open source link shortener that does this well and is hosted on Vercel is Dub.co
https://github.com/dubinc/dub