Absolute max voltage of Differential Signal
That is a very odd datasheet. Normally when we talk about "absolute maximum" ratings, we mean this table from page 4 in the datasheet:



These are requirements for how you must use the chip to avoid damaging it.

The spec you are referring to is in a table labelled "AC Characteristics". Normally a "characteristic" spec is a promise from the chipmaker about the behavior of the chip, not a requirement for how you should use the chip.

As I read it, they are promising that the output differential voltage will absolutely not exceed 1150 mV. A figure on page 8 tries to clarify what they mean by the spec:



I can't say how this relates to the requirements for your other chip without seeing the datasheet for the other chip.