That's because it didn't have a 2.5mm audio jack. How can it usher in the era of something it isn't a part of?

I believe that weird Motorola iTunes phone had 2.5mm

I believe the very first batch of the first generation did... I know someone who got one very early on and complained about it.

It did not. You might be thinking of the fact that the headphone jack was recessed in a way that caused many 3.5mm headphone plugs not to fit:

https://www.engadget.com/2007/06/30/iphone-doesnt-work-with-...

Ah, that sounds like a reasonable explanation.