Credit should probably go more to large markets like India and LatAm where texting is literally = Whatsapp. This would be an absolutely sane commercial decision for breaking into those countries.

They didn't need to allow it outside the EU which makes me wonder if they would have done it anyway.

Probably easier to allow for everyone than maintain a branched feature set. This is why strict regulation in one place (such as vehicle emissions rules in California) can propagate changes throughout the world.

Another W from the EU, though I'd hope Signal would be able to do the same.