Discovery vs Muon

With the most recent update to Plasma 5.5.3, I noticed Muon has been replaced with Discovery.
Is this a new package management app or a rebranding of Muon? I cannot find any information about this change.

Also, the changelog for Plasma 5.5.3 is here:
in case other forum and Netrunner users want to see the changes.

Discover is the new name for muon discover and is now part of Plasma 5 upstream.