Check out our new courses on Mobile Testing with BrowserStack App Automate. Login to Test University

To run iOS apps do I need to add BrowserStack iOS devices UDID to my provisioning profile?

No. On iOS, we resign apps with wildcard provisioning profile to install it on BrowserStack iOS devices. 

However, resigning of iOS apps would lead to removal of certain app entitlements such as App Groups, Associated Domains, Push Notifications, Keychain Access groups, Apple Pay, etc.