Well I can't say I've looked into it much so far, but I don't believe that's true. At least not the 'anything longer than 22-24' ' part.
Not sure if I'll even be able to swing a new trailer this year, depending on what the mowing season brings, so haven't been in a hurry to check them out specifically. But I do know that buying a trailer that's too small is worthless. A 22-24' trailer would be pointless for me. No point in buying one at all if it won't fit the configuration I need.
De-rating one would be a possibility I suppose. Tons (and I mean tons) of them running around here with no ICC numbers with the trailer sizes I have in mind. Bear in mind the weights I'm going to be hauling would likely never be over 10k (7k tractor with maybe a couple more attachments along for the ride). This is AG country, and DOT enforcement doesn't really fit the local culture. You could be dragging a trailer on it's side and on fire down the road and LEO's don't give you a second glance. H*ll, even seeing a guy with his load (equipment) chained down is a miracle (especially skid steers-don't know what it is about "skid steer guys" here, but none of them own any chains or binders).