I wonder if they left it in because they just wanted to be really, really sure there wouldn't be any getting stuck in bad states like some I2C devices can.
It's still used to allow for timing discrepancies between the physical layer and higher layers. Phys will insert and delete symbols in the IPG when the FIFOs between layers have too few or too many entries. This allows for systems with ever so slightly different clocks to talk to each other without any packet loss.