Hi,
Sorry for the late response.
In my opinion, using a level shifter is definitely a better option.
From what I understand from the BLVDS (TIA/EIA-899) standard receiver spec, this standard has an improved threshold. So, I think it should be possible to connect both the devices directly, as long as the transmitter drives output according to the receiver spec in standard. However, please consider the electrical aspects of it. I am not an expert in that, so would recommend you to run IBIS simulations before you do direct connections.
Regards.