Is it a violation of Apple's policy to use the Branch SDK without ATT opt-in?

No, it is not necessary to get user opt-in via the ATT policy in order to use Branch or load the Branch SDK.

There are numerous uses for UX and analytics tools (such as Branch) that do not fall within the scope of Apple's policies against tracking. Until/unless you receive ATT opt-in from a user, Branch helps you stay in compliance with the policy by not activating the functionality in our platform that provides device-level ad measurement.

For more details, please see:

• What counts as an 'ad' and 'tracking' under Apple's policy language?
• Are owned channels under the scope of Apple's new policy?
• Are organic/earned channels under the scope of Apple's new policy?
• Does Apple's new tracking policy block deep linking?