[saagarjha]

iMessage is backwards compatible with older devices. This means Apple can’t stop supporting old versions of the protocol, even as they are “cracked”.

[account42]

They could release updates for those older devices to unbreak them after protocol changes.

[saagarjha]

They could, but it seems like a lot of work for them. I am not sure they even have the pipeline to build old OSes anymore…