hello user16748,
no, each device need an unique encryption key, it’s not suggest to use the same encryption key for all devices.
as you can see in the developer guide, To Enhance initrd to Unlock an Encrypted Rootfs.
re-cap as following.
Unlock the encrypted root device with the per-device unique passphrase.
moreover, it’s not support to use generic passphrase, please have unique ECID to enable disk encryption. please have per-device flashing for mass production with disk encryption enabled.
you may see-also similar discussion threads for reference,
such as… Topic 263337, and Topic 265989.