Heres the official doc for MSP66. Mazda will replace the battery if youre throwing a P0DAB code. Otherwise its a flash.
To me, it seems like most of the battery issues arent actually battery issues and moreso software thats tripping DTC's even if within normal operating range. These updates seem to be changing the "buffer" for the CEL itself.
From another forum:
Parts Info: There are No parts required for MSP66 unless P0DAB is stored, in which case the 48-volt Battery will need to be replaced. Please note the replenishment of the MHEV battery is currently taking up to 3 weeks from time of order, due to capacity constraints with Mazda Japan’s supplier.
Car Use: Please explain to owner to continue to drive their vehicle while waiting for the replacement Battery to arrive.
Please explain to the customer the following functions maybe limited but does not affect the overall functionality of the vehicle, and it is still safe to drive.
• The engine warning light may illuminate
• The vehicle may be limited to engine-only operation due to fail-safe activation of EV assist, i-Stop and Regeneration functions may be disabled.
If the customer is uncomfortable with driving their vehicle, then please place them in a MCVP or other form of alternative transportation.