How could it not lead to more Signal-to-Signal chats?
The biggest problem with signal is that nobody uses Signal. Everybody uses WhatsApp.
If you make it so people can switch to signal without it completely cutting you off from the world, then more people will use it, which will lead to more Signal-to-Signal chats, which will lead to signal becoming widespread enough that people shift from WhatsApp.
There would be more people willing to try Signal because they would still be able to talk to people and not become a social outcast.
More people using signal would then mean more Signal-to-Signal chats.
More Signal-to-Signal chats is a good thing.