Don't think so. When pushing repeatedly down on the fender to get the suspension working - hood open - you can see the inside part of the mount moving up and down relative to the outside. I believe this is normal to some extent, and there is no sign of separation just some surface cracking - the rubber part of the mount appears to be 'flexing'. Also, using the picture on FastLane as a guide to the mount's design, it appears to be designed with 'bump stops' underneath to limit travel.
I suspect that when new, these stops would rarely connect. I'm wondering if the increased harshness is a sign that the rubber has deteriorated enough to bottom out routinely. If others haven't noticed this movement, perhaps it shouldn't be enough that I would have either?