Gonna post this here too.
So I wasn't crazy. I did some testing with one 3DS on 1.0.4 and the other on 1.0.3. I found that both Meta Knight's Down-Air and Up-Air have changed but it's not as exciting as I thought it would be.
D-Air & Up-Air's Sword-trails are now shorter to match their actual reach. F-Air, F-Tilt, & D-Smash still have their slightly deceptive sword trails. Even then, F-Air almost isn't even worth mentioning because the sword-trail is only very slightly inaccurate and F-Tilt isn't even a spacing tool so, if D-Smash gets fixed, MK will literally look good.
So no new hitboxes, just honest sword-trails. It really does make a big difference though. A lot less whiffed D-Airs or ruined Up-Air chains.