The 'Joint State Publish through hardware readings' part of Unit4 TF ROS101 seems rushed up will it be covered in more detail in ROS control?

The 3.2 section of UNIT4 of TF seems rushed off especially the controller aspect. Will this be explained in detail in ROS control?

Yeah, in the TF course, the controllers are note really explained in detail just because its not imprortant to know how TF works. You can learn more about that in the ROS control and also in the URDF course.