It's the wrong question.
The question should be "why would they want to?".
Signal solves a specific issue (private messaging), and decentralisation does not help with that at all. As far as i can tell it makes it harder.
Therefore there is no need to be compatible with a decentralised service like delta which solves a different need.
@newhinton well, I agree with the "why would they want to?" but for different reasons: they are not even federated across #signal servers how would they even think about being federated with something completely different
about your argument saying that federation does not help with private messaging, I disagree, federation makes it possible for you to self-host your server for your whole family and have them away from #Amazon or other centralized service's control, signal is a no-go
Yeah, but you are not talking about the same thing.
Signal is (only) about delivering a message from A to B, without C getting to know next to nothing about that.
Federation/Decentralisation is about making sure that your service cannot be controlled by a single entity.
Those two are entirely seperate issues that have next to nothing in common.
In this instance, decentralisation makes private messaging extremely hard, and would therefore downgrade signal.