Perhaps Canon won't share everything updated firmware will fix.
In an on going effort to keep us buying expensive OEM batteries that are always out of stock I can see them slipping in a fix in a firmware update that would prevent the use the of aftermarket batteries without telling us.
I know if no method to uninstall a firmware to a previous version.
I ordered an EOS RP that included one battery. The Canon website stated that battery was out of stock. I believe I signed up to be notified when the battery is in stock. I never received a back in stock email notification. It's been two years.
So guess what? I ordered two from Sterlingtek which arrived three days later. They hold a charge as good or better than OEM. Plus the battery is less expensive.
Unless Canon figures out a way to keep their OEM batteries in stock they might lose us to older Canon cameras that won't restrict us to OEM batteries.
The used market for newer camera may hit bottom if those very cameras won't use aftermarket batteries and OEM are not available.
My recently purchased 1Ds2 uses the Watson battery. I never would have bought the camera if it only uses the out of production OEM NP-E2 battery.
I bought mine from a women who is paying for her husband's cancer treatment. There's a variety of reasons people sell anything. To be stuck with a slightly used 1Ds2 because OEM batteries are not available would renders her camera worthless.
It's a good thing Canon flashes use AA batteries.
Button batteries for my vintage Nikon FM2 are readily available. Can you imagine all those vintage camera tossed into the trash because proprietary batteries are non-existent?
It appears to me that I should stay away from newer Canon product because one day OEM batteries will be unavailable and the product won't recognize aftermarket batteries.
