Are there any App Store Connect API updates being announced at WWDC19?

I don't know if there are any announcements, but the content of https://developer.apple.com/documentation/appstoreconnectapi/ changed dramatically:

All new "Provisioning" subheadline with pages for:

• Bundle IDs - Manage the bundle IDs that uniquely identify your apps.
• Bundle ID Capabilities - Manage the app capabilities for a bundle ID.
• Certificates - Create, download, and revoke signing certificates for app development and distribution.
• Devices - Register devices for development and testing.
• Profiles - Create, delete, and download provisioning profiles that enable app installations for development and distribution.