No article addresses ventilation, and the Bontrager website does not address ventilation, either. Huang at CyclingTips comments that Koroyd was poor at ventilation… but he then fails to compare the ventilation of Koroyd to the WaveCel helmets. I assume he hasn’t tested it; he expresses skepticism about ventilation in the comments, citing the lack of air channels.
I don’t see why the WaveCel material can’t be limited to being placed solely under the foam material of the helmet. I’m not convinced the WaveCel material is that useful when placed in the vents of the helmet, as it seems it will primarily be pushed through the vent upon collision.
I don’t think it will be that challenging for Specialized and Giro to release $300 helmets with similar safety, better ventilation and lighter. That said, the Bontrager WaveCel is a new benchmark in safety - no one will care if a helmet is lighter or has better ventilation than prior models by the same company if the new design doesn’t compete in terms of safety with the Bontrager WaveCel.