What is the impact of data layer project on the channels shown in Breakdown By Channel widget?

Milestone did a Data Layer implementation and channel mapping update project across all clients starting Jul 2019 which went on till Feb 2020. As part of this project, UTM tags in listings, campaigns default channel mapping in GA were updated. Because of these updates, channel wise data may show abrupt drops or rise as explained. This impact manifests itself in following ways:

You’ll see data for the social channel till August 2019, but from August 2019 we changed the rules and it is tracked as Organic Social and Paid Social like in the image below.

You will see some new channels: Local, Meta Search, OTA Referral, Other Advertising, Paid Social, Directory

You may see dip in traffic in following channels – Organic Search, Paid Search, Referral as their traffic is distributed into other newly created channels (Local, Directory, Meta Search, OTA Referral, Other Advertising, Paid Social) based on new UTM tags and channel mapping.