I can confirm. Recently I've mage Epic rolls for event characters and got a bunch of lvl 180 legendaries (those balanced ones that affect all stats), they are all weaker than IDENTICAL versions of lvl 165 legendaries and by a huge margin (over 20%).

Super sexy eternal knot (lvl 165)
All 4 stats ranging from 840 to 792 (crit at 11,36%)

Super sexy eternal knot (lvl 180)
All 4 stats ranging from 616 to 649 (crit at 8,64%)


This is huge difference for exactly same items placed 15 levels apart.

(As for other guy question, legendary items DO appear in shop, though very rarely, yesterday I had one appear, but because I was already in bed, I let it go since my iPhone has too small screen to even see what stats it had)