They just introduced firmware updates via SD card in the most recent released version, prior to that you had to put the printer online and associate it with an account to get firmware updates.

But yes today there is no need to use their cloud services unless you want to control the printer with their phone app. And the printer works totally fine completely isolated from the internet.

The now aborted proposed update would have required using a binary shim from bambu with an embedded 1 year lifetime SSL cert to speak the the printer at all, even when in lan mode.