So... that spiderman shirt... (new job tease)

[Shippuu]

Says who? POTD is used to level now from 1 all the way to 60.

While there's no confirmation, there is a high likelihood that PotD may not benefit someone past 60. When Heavensward launched, all the level 50 dungeons provided no experience points for quite some time because SE wants people in the new areas/dungeons. This same logic can be applied to PotD, ideally SE doesn't want people just cramming into PotD instead of actually doing the expansion content.