Maximum symmetrical swing requires Q point to be at the midpoint of AC load line
Yes, they are not the same.  Note that the first talks about the AC load line, and the second about the DC load line.

The AC and DC load lines can be quite different, depending on whether there are impedances around that are not purely resistive.  For example, a capacitor bypassing or partially bypassing a emitter resistor will cause the AC and DC load lines to not be the same.

The correct way to set the optimal operating point, assuming maximum symmetric output swing is the criterion, is to center it on the AC load line.  This is what your bolded sentence describes.  Using the midpoint of the DC load line is a shortcut that often works well enough.  When there are no reactive components around the transistor, then the AC and DC load lines are the same, so there is no difference between the two methods.