's line seems more limited seems to have dropped Phonak. Signia, Resound, Oticon and Sonic seem to be all they carry now

That disappointing. I wonder if Phonak stop providing to all these online sellers?

Phonak doesn’t supply to ANY online seller (excepting those that refer to clinics). Phonak sued BuyHear recently, and BuyHear agreed to stop selling Phonak products. Existing BuyHear customers who purchased Phonak products are not guaranteed to get service from Phonak (sounds crazy that they would deny warranty claims, but they might); this would leave BuyHear (or the customers themselves) on the hook for repairs, etc. It’s likely that the situation is the same with BuyHear and Oticon/Sonic.