You are wrong. It is an electronic device not a controlled substance. . There is no medical regulations on a processor or HA. They can be re-programmed to the new persons need. You own the device free and clear even if insurance paid for it. There are several CI parts/swap/trade sites and there are doctors/audiologists in all of them ( they wouldn't risk losing their licenses over something petty if it was illegal ) and this was confirmed by a lawyer.
People sell their old when upgraded or give to someone in need who cant afford a replacement. N5 and older models are being phased out due to the N6 and Kanso that recently came out, so members are scrambling to snatch up the older models for backups.
Insurance companies are strict with CPAP and require you to use it everyday, also it will be recorded to SD card to verify if you indeed use it, but no one care about CI if no one want to wear the processor anymore, but CI processor is expensive than CPAP.