Maybe. Retracted will almost always be safer than extended.
There is another lens, the EF 50mm f/1.4, that is well known to be more susceptible to damage from a relatively minor side impact to the front of the lens when the lens is focused to a closer distance and the front of the lens is extended out a little. When the lens is focused to infinity and the focus collar is fully retracted it is much less likely to be damaged because the tabs that engage the helical collar that effects the movement of the focus elements inside the lens are not parked at the weak point of the collar.
The original EF 24-70mm f/2.8 L is another lens known to suffer more from relatively minor bumps to the front of the lens when the barrel is extended. One of the key centering adjustments is located near the front element and can be moved out of adjustment. Since that particular lens is most extended at 24mm and most retracted at 70mm, it is much safer to keep the focal length set at 70mm when not in use so that the front tube is protected by being retracted into the main tube of the lens.
Pretty much any lens that extends for some settings and retracts for others will be more secure when retracted. How much that difference is will vary on a lens-to-lens basis depending on the individual design of each lens in question. Note that pretty much all compact cameras equipped with a permanently attached zoom lens retract the lens and park them in the shortest position during the shutdown process after you turn them off. This is deemed important enough that many of them also retract the lens after a period of inactivity or even if the battery power drops too low (so as to be sure the lens is retracted before there is not enough power left in the battery to retract the lens).