Perhaps one of the RU navy ships got the radar contact on the drone and vectored the MiGs.
The other B52 still has its transponder on so I think its nuke bomb drill target is Moscow based on the current approach.
The B52 heading towards Kalingrad-Moscow nuke drill is flying at 25,000 feet so they want Putin to see it.
USAF B52 Noble 41 descended to 10,000 feet for its flyby buzz of Kalingrad. Now it’s at 5,800 feet as it prepares for its practice run to nuke St Petersburg.