Maybe the close-in recon is something new - but otherwise it the same tactics we have heard for months - once Russia finds concentrations of Ukraine troops, they use artillery to simply lay waste to that piece of ground.
They send in troops once everything is pulverized. Not fast, and not elegant, but it may help them keep their own casualties low.
Its why the amount of Russian artillery fire is, supposedly, 10X Ukraine’s.
To push the "Evil Wagner War Crimes" Narrative, they have to admit Wagner is advancing and killing Uke (Military).
It's not new as you note, just new that ISW says it.
Bottom line: Russia is advancing and that is accurate news.
Zeepers will whine, ... and whine, ... and whine ...
Wagner attacks in three waves usually with arty in extremely close support
If last wave is unsuccessful they rely on arty