One of the key elements to respect in the Direct Message automation rules:
Misleading links: You may not send automated Tweets or Direct Messages containing links that are misleading, including links that maliciously or deceptively redirect through landing pages or ad pages before displaying the final content.
If your link shortening service is just that i.e. a redirect without a banner, ads or other framing then there should be no issue here. However, also keep in mind that the length of a Direct Message in text is up to 10,000 characters so broadly speaking there’s no reason to utilise a URL shortener here as there is no particular need to economise on the length of the text, and that will help to ensure that users are not mislead.
Also, be aware that all links posted on Twitter are automatically run through the t.co shortener so there’s no special benefit to adding another layer of shortening.
We reserve the right to review the use of our service at any time. If your app was previously reviewed by Twitter Platform Support then you should interact with the team via the appropriate form.