The float bowl vents allow a measured amount of air to contribute to the carburetors' proper operation. The bike can run w/o them but not as-well as if the tubes are in-place.
Back when the Kawasaki ZX-11 was new to market, one of the things that helped it to operate properly was a similar design for the carburetors, at highly-illegal speeds (not a concern during track days) where the air inlets feeding the carb bellmouths got a 'ram-air' effect from the engineered air inlets, the carburetors also had equalizer tubes like those on the VMax, so the ram-air at high road speeds would have those hoses to provide the proper air pressure to the float bowls, so the ram-air system would work properly. Cheap horsepower!
Sure, you can order almost anything on Amazon, but just measuring the inner diameter and matching it to that size for vacuum tubing at your local auto parts store should work. You could also fabricate some brackets like the OEM ones which are fitted at the front of the OEM airbox. Some sheet steel, and steel tubing, soldered or brazed/welded, wouldn't take much time, or you could see if 'the Usual Suspects' parts-breakers on here have them for purchase, if yours are missing. I use brake line tubing for fabrication like that, a better alloy for soldering/brazing/welding, & thicker walls.