I really don't think it matters what or if they are connected. They are just vents. As long as the line is routed from the T without a kink blocking airflow you're OK.
On mine I've had them routed to the airbox mostly. Once after it was serviced they guy ran them down over the swing arm. I didn't notice any functional change. The last time I had work done the vent hoses completely disappeared. Ran it this way several years until I discovered it recently. No issues. It seems the point of the hose is just to keep crud/water from getting into the T fittings between the carbs and thus the carbs themselves. Just my 2 cents.
