No, Point clouds, e.g. pointcloud.ply, do not have timestamp information
For general point cloud formats, there's no field for saving the timestamp information. Additionally, it is difficult to save the exact timestamp for a specific point as it could have been captured multiple times when scanning back and forth.
A three-dimensional representation of an environment, made up of many points. A point is defined by x, y and z coordinates, and it may or may not contain RGB, an intensity value, and normals.