It isn’t yet game over for disposable batteries. The following is a listing from the hearing aid guide on this site. I filtered by severe hearing loss (to limit it to prescription aids) and by receiver-in-canal aids (to exclude BTE and custom aids, where rechargeables mostly haven’t made inroads yet):
It lists 16 product families, but one of them is Jabra Enhance Select which is OTC, so it’s really 15 product families. 11 families include disposable battery RIC models. The 4 that don’t are Phonak Lumity, Starkey Genesis AI, Signia Pure IX, and Signia Styletto AX.
So right now 11 of 15 RIC product families have disposable battery options. As for where we’re going, the greater sales of rechargeable aids certainly is reason to worry for those of us who don’t want them. But I recall a recent post by @1Bluejay, saying that a Phonak rep told her they’re going to re-introduce disposables, which I assume means in Lumity or the followup flagship line. Meanwhile, there are disposable battery choices out there, and giving up on them won’t help keep them around in the future. I’m glad to have just bought a pair of Oticon Reals powered by 312 batteries.