projectgus ,
All True... Except for if you produce a design based to operate just under the maximum allowed specifications, then you are making a product that has inherently reduced reliability and longevity (for no good reason). Stay well away from the max specs for catastrophic electrical failure, and you'll be much, much happier.
Presumably, the DUE was designed for experimenter's and novices, using 'typical' (common) interfaces. While pushing the speed boundaries of the I2C bus is a possibility, anyone serious about it would most likely use an I2C buffer with rise/fall time acceleration (and not rely on a uC's raw dio pin for drive capability). Considering the intended audience, the DUE design should error on the safer-side of electrical failure.
I truly believe that the pull-up resistor choice on the DUE was a mistake, and it would have been done differently if they had the chance to do it all over again. These things do happen.
Also, remember, the installed pull-up resistors are 1000 ohms, not 1500 (as shown in the prints). Two DUE's connected together puts the I2C dio pins right near max spec.
Regards,
Chris