The hot-swappable flag means the ISO1640DWR handles live insertion without glitching the bus or latching up — the SDA/SCL lines stay high-impedance until the supply settles. That is the difference between a field-swappable module and a power-cycle-every-time design.
Propagation delay and timing margin
Max propagation delay is 70ns low-to-high, 88ns high-to-low, with pulse-width distortion capped at 45ns. The 24ns rise / 16ns fall times are typical.
No isolated power on board — the part draws its supply from the I2C bus side; you still need a separate isolated DC-DC if the two sides do not share a common ground reference.