I got spooked by the wheels looking out of alignment when I first noticed it, and even found a website giving step by step instructions on how to re-align the axles.
In the article (don't know the URL, sorry), it told how the loops in the ends of the leaf springs have plastic bushings inside that can wear. This is where the axle attachment to the trailer is made. The article said if the bushings wear, there can be more than usual axle movement.
After backing the trailer in, or when it is parked on unlevel ground I noticed more extreme axle mis-alignment. But if I stop the trailer when pulling in a straight line, the wheels all line up nice and straight.
The tires aren't showing any unusual wear patterns, so I came to the conclusion that the "looseness" of the axles must be a built in design factor. When pulling the trailer, the wheels naturally pull the axles into straight alignment, so there's no real problem.
However, if one of the wheels does warp, or if one or more ends of the axles bends a little, throwing the wheel(s) out of alignment with the axle, then I think that's when you'd see wear. Might need it professionally aligned, or the axle replaced at that point.
But I've decided that as long as the tires are wearing correctly, everything's cool. That would tell me the wheels are rolling true.
2011 Dodge Ram 1500 HEMI Quad Cab
2011 Jay Flight 26BH