^ Trussed streetlights haven't gone out of fashion in Illinois. They are still in the Highway Standards (see Pages 368/423 and 372/423)
However, the MN like davit style streetlights have become more common throughout the state, even in D1. Again, I am not a fan of this style in Illinois. Downstate, outside of D1, the aluminum truss style has become even less common (maybe except in D8, where I have seen installations in the past 10 years become somewhat common again). That said, I am sure this thread was referring to the stoplight structures, which are basically a dying breed in IL, though, still, plenty of legacy installations, luckily, still exist.