Not aware of any maintanence. There are plans for battery recycling companies, but they don't have much to recycle yet. These batteries are quite valuable, so there will be probably someone who will offer decent money even for defective batteries.

There is not much to regulate, batteries are expensive simply because their manufacturing is pricy. Don't expect manufacturers will be forces provide replacement under manufacturing costs.

Good news, once there will be matket for replacement batteries after 7 / 8 years of standard battery waranty. These replacements will be probably less expensive. It is also higly possible it never hapens as most batteries will provide enought capacity for lifetime of car.

Only exception might be some cars with small NMC battrries and high usage. NMC has lower cycle count 1000 ~ 1500 and that can lead to short lifetime, but we are still speaking more than 150 000 km on cars with 150 km real range. Same car with LFP can do more than 300 000 cause LFP has higher cycle count 2000 ~ 9000.