So in order to support this request you feel it is reasonable to require Apple to completely re-architect Siri, port the code from their neural engine implementation and figure out how to do this in a way that maintains privacy (despite it requiring that the voice itself be processed off the device, making it potentially subject to subpoena)? Just so I understand, since Apple would never use this service itself, I presume you would be OK with them charging these devices for all their development and operations costs?
What demands would Apple put on the device that would have anything to do with these requirements?
Since you seem not to understand, they are not sold out waiting for result, they are discontinued and no longer available. They sold out quickly when it was announced they were discontinued and many people who like them bought additional units.
In other words, this restriction cannot have anything to do with HomePod sales, as there will be no more HomePod sales, and this feature was not announced until well after they were almost complete sold out.