AutoCAD 2016 introduced an improved revision cloud and with it comes a new system variable, RevCloudGrips. The revision cloud made when that system variable is set to On will allow you to grip edit the revision cloud much easier than before. If you have made a revision cloud from a polygon, then the grips will work the same as the geometric shape it was made from. If you used a rectangle to create the revision cloud, then the grips to edit that cloud will be the same ones for a rectangle. One made from a circle will have grips similar to a circle.
Notes from Cadalyst tip reviewer R.K. McSwain: AutoCAD 2016 introduced some new revision cloud tools, and this is a good description of one of the new features. Using an existing object as a starting point for your revision cloud gives you more control over future edits.