So, random bushings of an unknown manufacturer and unknown age, not to mention unknown history, are going to dictate your opinion on this. Rubber bushings deteriorate over time too, you know. Especially the new ones.
I've heard this old wives tale before, and despite using poly bushings in multiple different applications for decades and tens of thousands of miles I've never seen anything like it. It's almost like if you maintain them properly that doesn't happen.
Nevermind the fact that the topic at hand, adjustable strut rods, don't use poly bushings.