X-Rods not glued? Possible defect?

I needed to replace several parts of my printer, including the fan, so I was reading the Fan Replacement guide here:

https://printm3d.com/solutions/article.php?id=73

And the very first line caught my eye: "One side of the X Rods will be glued to the sliders, one side will not."

Wait, is one side of these these supposed to be glued? Because mine never were, and I always wondered if that was normal, because the rods actually slightly move due to the gap from not being held down in any way whenever the printer calibrates it's x/y axis before a print.

Does anyone here have X-Axis that are glued down? If so, which side? And would it be a good idea to glue mine then to avoid issues/inaccuracies? I think the rods might slightly be moving during movements/homing because they are not glued down.

not a clue, maybe ask the micro3d people ?