How would they be able to switch it to 16 x 9 though? Its not like we're talking about live action sitcoms, which were usually filmed in widescreen and then cut down to fit the size of old standard TVs. There's no raw widescreen footage of the animation cells. Unless they're just cropping/resizing the image in which case... ick.
The show was actually animated in 16x9 and the sides were cut down to fit the size of old standard TVs from the second season of Justice League onwards. That's why the JL season 1 blu-ray is pillarboxed while the season 2 and JLU blu-rays are 16x9 widescreen.
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