The UV Rotator is now under the UV menu.

MaterialGraphProject/Assets/Vlad/UVRotatorNode.cs

 
 namespace UnityEngine.MaterialGraph
 {
-    [Title("Math/UVOperations/Rotator")]
+    [Title("UV/Rotator")]
     public class UVRotatorNode : Function2Input, IGeneratesFunction
     {
         private const string kUVSlotName = "UV";