I thought about that, and I'm not sure it actually changes anything. So you want to register a new device with your Signal account and you don't have the previ

I thought about that, and I'm not sure it actually changes anything. So you want to register a new device with your Signal account and you don't have the previous device, either because you're a malicious attacker or you lost or destroyed it. Covering the attacker case, presumably you already can't access the message history. I don't see how you could reasonably do anything different for the lost device case, but I guess it's not that big a deal to lose message history. But if the message history is already gone either way, why not make it a entirely new and separate account?