Just for fun??

On a car equipped with a mass airflow sensor located prior to the blowoff valve, venting to atmosphere confuses the engine control unit (ECU) of the car. The ECU is told it has a specific amount of air in the intake system, and injects fuel accordingly. The amount of air released by the blowoff valve is not taken into consideration and the engine runs rich for a period of time.
Typically this isn't a major issue, but sometimes it can lead to hesitation or stalling of the engine when the throttle is closed. This situation worsens with higher boost pressures. Eventually this can foul spark plugs and destroy the catalytic converter (when running rich, not all the fuel is properly burned in the cylinder which can allow unburned fuel to combust upon contact with and melt the converter or to cause incompletely combusted fuel to leave heavy carbon deposits).

Opinions on this statement?

 

most of this is correct, although I doubt the venting of the BOV to atmosphere would lead to a melted cat in and of itself. It runs rich for a split second which is why most of the time, the car doesn't even stall. The first WOT pull you did should burn everything off again. It's more likely that melted cats would be a direct result of running too rich under high load.