We're in close communication with the Twitter team. They are supporting Apple's SKAdNetwork framework. Rather than forwarding Postbacks like many other networks, Twitter is sharing this data with MMPs (including Branch) via an aggregate API. This means we are able to ingest campaign results data, and continue providing aggregate reporting for your Twitter ads.
This data is available in the Branch dashboard as long as you have enabled and authenticated with Twitter in the Partner Management section of the dashboard and have authenticated your app for SKAdNetwork reporting; no additional action is needed for this data to start flowing.