Microsoft is preparing new major release of Microsoft Dynamic 365 (CRM).
Majority of user should start using the new modern client aka Unified interface, so Microsoft needs to close the gaps between the old UI and new UI.
If you have been missing the Advanced find and Merge feature in the new UI, you don't have to be worried anymore.
In the latest version, these features are included in the new Unified Interface.
They have the same design as the old UI, but they work OK in standard browsers.
From my point of view, it is a step forward. I'm looking forward to optimization of these features to make them work in all clients (mobile, tablets etc.)
Have a good day