Just checked out SteamDB that new build was issued 47 minutes ago, it was almost 2 weeks break before last build, and there was some news sprinkled in CDPR's investors call in 31th of May about next patch coming in couple of weeks.
Last week I noted that the DLC folder containing mostly wallpapers and mp3-files was updated last week with DLC Extra Info which appears hidden to public.
This could be promotion material for Expansion reveal, or perhaps just DLC or other content that was cut out coming back?
It could be even small multiplayer addition, considering they're now openly having it in on their Job search page.
There has been a lot of talk about starting to turn things around in April and this seems like it could be big, not necessarily content wise as they mentioned it's NOT going to be their "biggest patch", but could start seeing some big improvement in some key areas.
Edit Update 16.06.2021:
Seems like release branch is prepared as well and there wasn't a new build required to fix issues with the new patch.